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BY 4.0 license Open Access Published by De Gruyter Open Access June 17, 2022

Households and Hamlets of the Brześć Kujawski Group

Peter Bogucki and Ryszard Grygiel
From the journal Open Archaeology


Over several decades, we have written extensively about the household as a fundamental organizational unit of the Neolithic society. Starting from our definition of the household cluster at Brześć Kujawski 3 and the detailed analysis of household activities at House 56 at Brześć Kujawski 4, we continue to consider the household as the locus of decision-making and resource allocation even as our thinking has evolved over the intervening years. At the same time, Neolithic households functioned within local concentrations of settlement in which they interacted with other such units. We characterize such local social entities as “hamlets,” adapting the definition used by the anthropologist Frank Cancian to refer to institutionalized alliances of domestic groups in which affiliation is demonstrated through residential proximity. We have studied two such hamlets of the Brześć Kujawski Group: the Osłonki-Miechowice-Konary hamlet and the Smętowo hamlet consisting of Brześć Kujawski and Pikutkowo. We characterize these hamlets to show how they extend our original conception of household-based societies to develop a robust understanding of local Neolithic communities.

In his 1958 article, “Study of the Neolithic Social Grouping: Examples from the New World,” Kwang-Chih Chang wrote: “I suggest that it should be the archaeologist’s first duty to delimit local social groups such as households, communities, and aggregates, rather than to identify archaeological regions and areas by time-spacing material traits, since cultural traits are meaningless unless described in their social context (Chang, 1958, p. 325).” In the next paragraph, Chang pointed out that although his article was limited to New World examples, such analysis could also be applied to cases in the Old World. In particular, he wrote, “the Danubian villages at Brześć Kujawski and Köln-Lindenthal…are fairly complete village sites where such a community patterning study seems possible.” This mention marked the first appearance of Brześć Kujawski in a North American archaeological journal and pointed clearly to the potential of Neolithic sites for the analysis of social organization at the local level. Chang’s article is also perhaps the first mention of the household as a social entity meriting archeological study.[1]

The year 2021 marked the 40th anniversary of our 1981 article “The household cluster at Brześć Kujawski 3: small-site methodology in the Polish lowlands” in World Archaeology and the 35th anniversary of the publication of Grygiel’s (1986) “Dom z podwórzem jako reprezentacja archeologiczna podstawowej jednostki społecznej w grupie brzesko-kujawskiej kultury lendzielskiej”[2] in Prace i Materiały Muzeum Archeologicznego i Etnograficznego w Łodzi. It is fitting, then, that we have this opportunity to recognize the lifetime contributions of Lech Czerniak, whose studies of sites of the Brześć Kujawski Group of have advanced research on settlement patterning and longhouse architecture. His studies of longhouse settlements at Krusza Zamkowa, Zelgno, and Racot among others have been immensely important for understanding the variability as well as the common features of such sites.

The goal of this article is to revisit our thinking about the households of the Brześć Kujawski Group in the lower Vistula valley and adjacent parts of the Notec and Warta drainages during the second half of the fifth millennium B.C. (Figure 1).[3] We would first like to put some context around our initial forays into this subject during the 1980s. The reader might find this to be of historical interest, along with the aforementioned quote from Chang. We will then point to new data that have emerged since the 1980s that provide additional dimensions to household activities. Finally, we will reflect on the linkage between households and larger communities of the Brześć Kujawski Group, which we term “hamlets.” The concept of the hamlet allows us to frame the aggregations of households such as those seen around Brześć Kujawski and Osłonki in a larger picture taking into account dynamic relationships among households, particularly in the emergence of nascent social differentiation.

Figure 1 
            Map of lower Vistula valley and adjacent parts of the Warta-Notec drainage showing areas of settlement of the Brześć Kujawski Group (shaded) and sites mentioned in text, in order of appearance. Key: (1) Brześć Kujawski 3, 4; (2) Biskupin 15a; (3) Krusza Zamkowa 3; (4) Kościelec Kujawski 16; (5) Osłonki 1, 1a/Konary 1, 1a/Miechowice 4, 4a; (6) Racot 18; (7) Zelgno 12; (8) Kruszynek 6/Ludwinowo 2, 3; (9) Bodzia 1/Dubielewo 8; (10) Żygląd 26.

Figure 1

Map of lower Vistula valley and adjacent parts of the Warta-Notec drainage showing areas of settlement of the Brześć Kujawski Group (shaded) and sites mentioned in text, in order of appearance. Key: (1) Brześć Kujawski 3, 4; (2) Biskupin 15a; (3) Krusza Zamkowa 3; (4) Kościelec Kujawski 16; (5) Osłonki 1, 1a/Konary 1, 1a/Miechowice 4, 4a; (6) Racot 18; (7) Zelgno 12; (8) Kruszynek 6/Ludwinowo 2, 3; (9) Bodzia 1/Dubielewo 8; (10) Żygląd 26.

1 Our Early Interest in Households

The motivation for our 1981 article in World Archaeology (Bogucki & Grygiel 1981) actually came from two sources. The first was the introduction of the “household cluster” as a way of talking about fundamental configurations of archeological remains that included a house and adjacent features including storage and rubbish pits and burials found in the 1976 volume edited by Flannery The Early Mesoamerican Village. For many like Bogucki who were graduate students in the late 1970s, this book had a tremendous impact on how we looked at archeological sites. Marcus Winter’s first chapter on household clusters at San José Mogote was really the definition we sought to emulate (Winter, 1976). The period under discussion was the Formative, the New World analog of the European Neolithic, which also made the connection relevant.

Our second influence, often overlooked, is the proposition advanced by Michael Moseley and Carol Mackey that the study of large complex sites on the Peruvian coast could be advanced by the investigation of small, simple sites at which elemental configurations of features could be identified (Moseley & Mackey, 1972). These elemental structures could then be sought in larger sites to disentangle their spatial patterning. At the time, we were taken by the contrast between the smaller site of Brześć Kujawski 3 with its single house (two congruent structures over time) and the larger, complicated palimpsest presented by the site plan of Brześć Kujawski 4 that had caught the attention of Chang two decades earlier. The relevance of Moseley and Mackey’s approach of using simple small sites to understand complex large ones resonated strongly with us. Together, these Americanist contributions to archeological practice in the 1970s provided the fundamental motivation for our 1981 article, which we sent to World Archaeology for inclusion in a Miscellany issue.

Subsequently, in 1982, the Tozzer Library at Harvard was disposing of a worn-out copy of The Early Mesoamerican Village, which Bogucki rescued from the discard shelf. He sent it to Grygiel in Łódź so he would have his own copy and would be able to examine it in greater detail, especially the chapters following Winter’s introduction. At this time, Grygiel had returned to Site 4 at Brześć Kujawski. Over the course of several summers, he excavated House 56 and its associated features. Bogucki was not involved in this fieldwork other than a brief visit in the summer of 1982, so he had no idea where Grygiel’s analysis of the finds and features of these seasons was headed. When Bogucki was next in Poland in 1984, Grygiel presented his monograph about the household cluster at House 56 with a wealth of detail about household activities and structure clearly influenced by The Early Mesoamerican Village.[4]

Others were thinking along similar lines. In 1982, Wilk and Rathje edited a special issue of American Behavioral Scientist entitled “Archaeology and the Household: Building a Prehistory of Domestic Life” containing articles, which established some foundational principles for studying archaeological households. Another development in 1982 was the emergence of the research group working on the Aldenhovener Platte in the Rhineland of the concept of the Hofplatz as an elemental unit of Linear Pottery settlement organization (Boelicke, 1982; Lüning, 1982). The Hofplatz is essentially a household cluster, except that the Linear Pottery sites of the Rhineland did not have intramural burials, at least none that survived in the loess. The notion of the house and its associated features and activity areas, however, were very much aligned with Winter’s household cluster at San José Mogote, our analysis of Brześć Kujawski 3, and the household archeology discussed in Wilk and Rathje’s volume. The household as the basic unit of settlement structure seemed to be validated through the growing level of interest.

As we were formulating our household model for Brześć Kujawski 3, Ruth Tringham was working on the interpretation of excavated materials from the Vinča site at Selevac-Staro Selo in Serbia. Tringham was Bogucki’s Ph.D. adviser at Harvard, but she departed for Berkeley in 1978. As a result, in these pre-Internet days, she and Bogucki did not have opportunities to exchange ideas on specifically this topic. Thus, our approaches were really two discrete lines of archeological thought during the first years of the 1980s. At the 1983 meetings of the Society for American Archaeology in Pittsburgh, Tringham presented a paper entitled “The Development of the Household as the Primary Unit of Production in Neolithic and Eneolithic South-east Europe,” which resonated strongly with Bogucki.[5] In particular, her argument, as later articulated in print (Tringham, Brukner, & Voytek, 1985, p. 427), was that the “household, with its regular cycle of demographic and economic growth and decline, promotes long-term stability in social organization in which short-term inequalities rather than cumulative salient ranking are a characteristic feature.” Here, then, there was a link between our methodological analysis of the finds from Brześć Kujawski 3 and their interpretation in a broader anthropological framework.

Bogucki (1988) then developed the notion of households as fundamental decision-making units of the Neolithic society, enabling the spread of farming in central Europe. In his view, the autonomy of households to decide to relocate provided the “metabolism” of the diaspora of the Linear Pottery culture during the sixth millennium B.C. and began the successful adaptive pattern seen in the Danubian societies of the following millennium. Meanwhile, Grygiel brought our approach to household archeology together with the Hofplatz model at the 1988 conference on the Lengyel culture in Nové Vozokany, Slovakia, which resulted in a substantial elaboration of the social dimensions of our earlier work (Grygiel, 1994).

From the outset, we believed that there was a correlation between the occupants of a single longhouse and a residential group comprised of related individuals that functioned as a household in its pooling of resources and decision-making. We did not admit the possibility that a Neolithic longhouse might accommodate multiple discrete groups that constituted separate households but instead chose to make the fundamental assumption of “one house = one household” regardless of the size of the longhouse or the exact composition of the residential group that inhabited it. The consistent repetition of the same complex of features in similar proportions was central to this assumption. We continue to believe this to have been the case for the Brześć Kujawski Group and its congeners, although the actual composition and the size of each household might have varied. Perhaps, it did include more than one familial unit. We recognize that other longhouse societies (e.g. the densely nucleated Iroquois communities of eastern North America) had vastly different living arrangements with multiple discrete households living within superficially similar buildings. At the same time, as Bogucki (2003) noted, we cannot assume that everyone within each Neolithic household was similarly aligned in terms of their motivations, goals, and practices, even if they were close kin.

2 Household Clusters of the Brześć Kujawski Group, Updated

In hindsight of 40 years, over which many more settlements of the Brześć Kujawski Group have been excavated, we would now like to update our original model of a “standard” household cluster.[6] As originally conceived, four principal types of features constituted the elements of household clusters of the Brześć Kujawski Group. Each such cluster has a house (or more, if rebuilt in roughly the same location), one or two clay-extraction pits, several smaller pits, and several burials. We drew a distinction between the clay-extraction pits (glinianki in Polish) and other pits, which served less-distinct purposes. The clay-extraction pits functioned as artifact traps, but not all have deliberate rubbish depositions. Often, they have low densities of artifacts, the product of accidental inclusion during the blending and smearing of discarded materials across the site surface, although occasionally a concentration of artifacts will reveal an episode of rubbish deposition. Other pits seem to have been used variously. Some were intentionally used for storage, such as pits at Brześć Kujawski 3, which were interpreted as having been used for the live storage of aquatic resources like shellfish and turtles. Others were repositories of debris from production, such as a feature at Brześć Kujawski 4 in which by-products of antler working were found. A nearby pit also showed that shell beads were manufactured in a domestic context, while at Brześć Kujawski 3, the intermingled skinned carcasses of five beavers revealed another domestic activity. These features may reflect household-level craft specialization, a topic worth exploring in greater detail.

2.1 Burials and “Microcemeteries”

Human burials were integral parts of the domestic complex of the house and associated features, in light of the practice of the Brześć Kujawski Group in burying many if not all of its dead within settlements rather than in extramural cemeteries that have never been found. The household context of burials is significant, for it indicates that such a domestic unit was a central organizing principle of this society even in death. Ancestors continued to be part of the domestic unit and were NOT relegated to a distant cemetery. Burials, then, tell us something about the life story of these households. Studying this is easier where we can assign them to specific household clusters, as in several cases at Brześć Kujawski, much more difficult at sites like Osłonki where there are many more houses and a denser palimpsest of features.

At some settlements of the Brześć Kujawski Group, burials often do not occur singly and dispersed but rather form clusters of 2–9 graves, often lying roughly in parallel. It is common for the graves to be of varying depths and to have differences in their furnishings, suggesting they do not represent multiple concurrent deaths. We can refer to these clusters as “microcemeteries” using a term coined by Scarre (2004). In order to create such microcemeteries, it would have been necessary to have above-ground indications of previous burials, such as small mounds, wooden posts, or slabs of stone. Earlier graves in each cluster do not appear to have been disturbed by later graves, suggesting that these areas were recognized as burial plots during the occupation by the Brześć Kujawski Group. The microcemeteries are an important example of “memory work” by members of individual households (Bogucki, 2014).

2.2 “Cellar Pits” in the Brześć Kujawski Household Cluster

An element missing from our original conception of the household cluster was the “cellar” feature that now is seen in the interior of many longhouses of the Brześć Kujawski Group. It was not observed in the longhouses on Brześć Kujawski 3, houses 41 and 42, excavated by Jażdżewski and Madajski in the 1930s. In hindsight, we should have made a note of such a cellar feature in House 55, which we had excavated in 1977 at Brześć Kujawski 4, where it is very clearly visible. On published house plans from other sites excavated before 1980, cellar pits are very clearly seen. For example, House 1 at Dobre 6 (Jażdżewski, 1938, Figure 41) has a very clear cellar feature. At Biskupin 15a, two elongated pits (perhaps the remains of one long one before the topsoil and cultural layer were stripped) were plainly visible (Maciejewski, 1956, Figure 1). Maciejewski (1956, p. 28) described these pits in the typical way that has come to be used for such features: “Pits 8 and 14 were within the house, parallel to the eastern interior wall…” Pit 8 at Biskupin 15a in particular has the classic oblong, “bathtub” form.

Once one becomes aware of these oblong features, they can be recognized in many published house plans of the Brześć Kujawski Group dating back several decades.[7] Pit 576 at Krusza Zamkowa 3 stands out clearly in the interior of its excavated house (Czerniak, 1980, Figure 49). The house at Kościelec Kujawski 16 has a double-pit feature similar to the one at Biskupin, and its oval shape and alignment parallel to the eastern wall of the house were noted by Czerniak (1979, p. 80). Today, oblong interior features along the eastern wall can be seen at many, if not the majority, of complete house plans of the Brześć Kujawski Group, particularly those assignable to Grygiel’s Classic phase. For example, on the site plan of the settlement at Bodzia (as published by Kabaciński et al., 2014), the “cellar” feature appears in virtually every house (Figure 2).

Figure 2 
                  Houses of the Brześć Kujawski Group with distinct cellar pits at Bodzia 1 (abridged from Kabaciński et al., 2014, Figure 2).

Figure 2

Houses of the Brześć Kujawski Group with distinct cellar pits at Bodzia 1 (abridged from Kabaciński et al., 2014, Figure 2).

When we began excavations at Osłonki in 1989, oval features along the eastern walls of longhouses appeared with the first house we found, Pit 8 in House 1. Over the next several seasons, we found more cellar pits in many of the better-preserved houses. Some of the most clearly delineated are Pits 54–54 (House 5), 111 (9), 116 (10), 149–208 (23), 204 (14), 272 (26), and 275 (33). We did not immediately recognize that they were such distinctive and recurring elements of the Brześć Kujawski household cluster, however. In our preliminary report, we simply wrote, “Some pits, which are oval in plan, 3–4 sq m. in surface area and a meter or more deep, are found in the interiors of longhouses and may have served as storage pits while the houses were occupied (Grygiel & Bogucki, 1997, p. 169).”

Lech Czerniak was perhaps the first to refer to these features as “cellars” in print and pointed out that they occurred also at sites like Racot 18 in Wielkopolska and Zelgno 12 in Chełmno Land, outside the core area of settlement in Kuyavia (Czerniak, 2002, pp. 12, 19). It became obvious that the presence of such features was very much the rule rather than the exception, so their functional assessment as cellars had become standard when it was time to present the results of the research at Osłonki and sites at Konary and Miechowice (Grygiel, 2008). His re-examination of the finds from Brześć Kujawski 4 led Grygiel (2008, p. 120) to posit the presence of a hitherto-unrecorded longhouse 56a alongside the celebrated House 56. Czerniak and Pyzel (2016, p. 102) have suggested that the presence of such oblong pits can potentially be taken as proxy indicators of a longhouse even if the bedding trenches themselves have eroded away.

Thus, our original 1980s definition of the household cluster at settlements of the Brześć Kujawski Group can be updated to include two distinctive elements: (1) the clustering of burials into what can be termed “microcemeteries” associated with some houses (although other houses are associated with one or no burials; the density of burials on sites of the Brześć Kujawski Group varies considerably), and (2) a very specific form of the interior pit, oblong in shape and regular in profile, found inside the eastern wall of houses, which today is commonly termed a “cellar” due to its presumed storage function. These two elements add further dimensions to the patterning of human behavior within these domestic units.

3 Connecting Household Clusters to Social Organization

As we noted earlier, from the outset, we have assumed that there is a direct correlation between household clusters and the basic units of production, pooling, and decision-making. This may have been naïve, for it did not take into account that individual structures or compounds might contain multiple households (which we do not believe to have been the case in our particular context), and at the same time, within a household, there could be divergent motivations and goals (which could well have happened.) The household, as imposed on the archaeological household clusters, is an analytical abstraction. Our preference is not to unpack it too much. We recognize that households will manifest themselves differently in different parts of the world. Homologies in building types and settlement layouts do not imply that all configurations of households are identical.

Tringham and Krstić (1990, p. 603) argued “It is not essential to be able to identify ‘households’ in the historical and anthropological sense of the term. It is sufficient to be able to investigate changes in co-residence and cooperative activities of domestic groups on an archaeological site.” In their view, the term “household” functions as a concise way of saying “kin-based co-resident domestic group.” They note that competition among such units and the inequalities inherent in their developmental cycle over time would have formed the basis for the emergence of social differentiation during this period.

3.1 From Household Clusters to Households

The principal goal of studying household clusters is to try to understand the lived experience of the individuals who inhabited them. As Lightfoot (1994, p. 12) notes, households are defined by their behavior. Household clusters are considered to be material traces of a residential group corresponding to a farming household, which made fundamental decisions about the acquisition, allocation, consumption, and disposal of resources. Each settlement was composed of several contemporaneous households, up to about a dozen in the case of Brześć Kujawski 4. The frequent rebuilding of houses contributes to an impression of much larger and denser agglomerations of population.

The use of the household as an analytical unit in archaeology has a particular justification, in that it provides a context in which settlement remains can be linked to a “real” social group that can be isolated and compared in a meaningful way. The analysis of settlement remains at the household level is more than just the use of a “convenient” unit of analysis but rather an attempt to structure the archeological record in a way that we can begin to approach economic and political institutions beyond the household. In other words, the study of archeological households allows us to study prehistoric society “from the bottom up,” a phrase that quickly came into use at the beginning of household archeology.

Households of the Brześć Kujawski Group would have differed in the number of members, their access to resources and accumulation of property, and the skill with which they were managed. Relations of kinship, friendship, and trust would have developed with some households both near and far, while with others there would have been animosity, distrust, and spite. They would have needed to work out access rights to arable land, grazing, and timber among themselves. Each would have been in a competitive relationship with the others, with relations of status and power being characterized by ephemeral asymmetries.

A particularly important distinction lies among different forms of prestige and power within the household, specifically between the political agenda of the household in the community and its economic activities. For example, men might be dominant in the sphere of public politics in a community, yet in terms of economic organization, their spouses may be relatively autonomous actors, engaging in their own productive activities. At a certain point, however, their interests converge, and a household identity emerges.

3.2 Household Cycles and Social Differentiation

We propose that several elements underlie the Neolithic household’s role in the emergence of social differentiation.[8] First, households pursue strategies of accumulation in order to create wealth that can be passed from one generation to the next, thus ensuring the viability of offspring households. The second is that each household follows a developmental cycle, which progresses from the formation to their dissolution, as members are born, mature, and die. The third is that households find themselves in asymmetrical social and economic relationships with each other depending on where they are at different points in this developmental cycle. Finally, leadership emerges from successful management of the affairs of a household, which then permits the attraction of adherents and debtors, leading in turn to the growth of factions.

Each household, as a self-interested economic unit, can be said to pursue a strategy of accumulation by looking for opportunities to acquire resources, property, favors, and obligations to provide economic and social security and possibly advancement. The fact that different households will have different degrees of success in the pursuit of their accumulation strategies does not automatically imply social differentiation. Indeed, many societies have built-in leveling mechanisms that put a damper on excessive accumulation. Some households take risks, while others manage resources conservatively. Members of a household are prone to disease, accidents, and death. Livestock is vulnerable to disease, predation, and theft. Bad decisions were probably just as much a reality of prehistoric life as they are today. Initiative, resourcefulness, and luck were as important 6,000 years ago as they are today. Hazards have varying impacts on households of differing sizes, compositions, holdings, and reserves. The mere fact of household accumulation does not in itself lead to long-term permanent inequalities between households.

Each household undergoes a developmental cycle, leading from its founding to its eventual dissolution. In his classic 1958 discussion of this process,[9] Fortes describes five stages of development:

  1. Establishment – the new household, possibly still dependent on its parental household(s), builds a house and establishes a farm.

  2. Expansion – the new household becomes clearly independent and children are born;

  3. Consolidation – the household expands to its fullest point.

  4. Fission – children begin to marry and leave the parental household, perhaps associated with the relinquishment of control over household resources from the parental to the filial generation.

  5. Decline – the final stage, which often contributes to the expansion stage of filial households, if the parental household becomes lodged in them.

Such an idealized household model may not have applied exactly to Neolithic societies in temperate Europe, but the important point is that Neolithic households certainly experienced a similar cyclical developmental process tied to reproduction, aging, and family structure. Fortes’ model assumes a two-generation structure of households and their filia. In many societies, these stages may not be so clear cut, especially if the development takes place over three generations as children remain in parental households after marriage and birth of their first children. In polygynous households, a single residential group may be going through several stages simultaneously in different subsections. Thus, the household structure is constantly changing, and a community composed of multiple households has extremely dynamic demographic activity at the household level. Similarly, the relationships between parental households and those of their offspring, as well as between them and other households into which they have entered into alliances through marriage and betrothal, are constantly shifting. This process provides for the transfer of assets from the parental household to its filia to ensure the eventual establishment of new households as viable economic units.

As a result of this developmental cycle, neighboring households often find themselves in an asymmetrical relationship with each other, depending on where they are in the developmental cycle. These social and economic asymmetries could be characterized as “inequality” (e.g. Tringham & Krstić, 1990, p. 606), except they are neither permanent nor cumulative. For this reason, we prefer to characterize such asymmetries as “social differentiation.” So long as the range of variation in the abilities of different households to accumulate and disperse assets falls within a very narrow range, each household can expect to find itself at different times on both the plus side and the minus side of this asymmetry. Some households are in the ascendance of their accumulation cycle, while others are in eclipse.

3.3 Transegalitarian Households

Thus, inherent inequalities exist within any agrarian community composed of households. In Neolithic societies, these patterns of social relationships are very difficult to perceive archaeologically, since they are ephemeral and uncumulative. Such societies might be called “transegalitarian” (Blake & Clark, 1999) since they are neither completely egalitarian nor ranked in any permanent or formal manner. Competition among households produces short-term asymmetries in wealth and power. Clearly, these asymmetries contribute to the construction of identities within specific households and also form the basis for differences in status, power, and wealth.

We see the Brześć Kujawski Group as such a transegalitarian society during the fifth millennium B.C. in central Europe. Recent insights into asymmetries among households at Osłonki come from the stable isotope analyses of Chelsea Budd (Budd et al., 2020). Her work shows subtle but significant differences in dietary quality between individuals buried with copper ornaments compared with those who lacked such grave goods. This work, as well as archeogenetic investigations (e.g. Lorkiewicz et al., 2015), opens new avenues for investigating the variability among households at sites of the Brześć Kujawski Group.

The central activity of the Neolithic households at these sites was extraction from the environment of all sorts of resources: crops, livestock, wild animals and plants, fish, shellfish, turtles, waterfowl, shed antlers, timber and fuelwood, clay, local stone, and local flint. This labor-intensive activity not only supported the household but also fueled the acquisition of copper and good flint, and the more labor a household could command translated into greater opportunity to acquire these exotic materials. While nonlocal flint was superior to local erratic flint in its flaking qualities, the local material was perfectly adequate for most tasks. The copper was used for personal ornamentation, certainly of the dead, perhaps also of the living, instead of for a functional purpose. They did not need these exotic materials, but they wanted them. One might even say that the inhabitants of these sites embraced an “ideology of accumulation.”

We now know a lot more about the people who inhabited the households of the Brześć Kujawski Group, thanks to the work of Lorkiewicz (2012) and his research group who studied the human skeletons from Brześć Kujawski, Osłonki, Miechowice, and several other nearby sites. The sample comprised the skeletons of 41 children, 28 adolescents, and 117 adults. We know that they had a physically challenging life. Facets on heel bones indicate habitual squatting, while Schmorl’s nodes on the vertebrae are signs of hard labor. Many bones bear traces of osteoarthritis. Dietary pathologies include enamel hypoplasia and cribra orbitalia. Violence was a fact of life. Some, mostly males but at least one female, had suffered cranial trauma, which had resulted in their deaths. Adults of all age grades, both male and female, and a significant number of children lived on settlements of the Brześć Kujawski Group. This would suggest the presence of fully functioning households proceeding through their developmental cycle. The injuries also suggest a population that resorted to violence rather than relocation to resolve personal conflicts.

Lavish displays of copper, shell beads, and bone armlets in burials capture the success of individual households at particular moments in their developmental cycle. Variation in richness and variety of grave goods results both from the inclusion of symbols of maleness (antler axes, flint blades, bone points) and femaleness (shell hip belts) and from individual households’ ability to convert the fruits of their labor into expensive and exotic materials like shell beads, carved bone armlets, and copper. If household economies were characterized by the pooling of contributions from their members, then perhaps displays of personal ornament in the graves can be taken as a reflection of the value of that individual’s contribution to the success of the household at a moment in its cycle of development and accumulation. Burials with particularly rich arrays of copper goods, such as Grave LIV at Osłonki (Grygiel, 2008, pp. 951–953), may signal households at the apogee of their accumulation.

4 Hamlets of the Brześć Kujawski Group

A difference between the study of households in Americanist archeology and that seen in some European, mainly British, approaches lies in how the household is conceived as relating to its larger community. The Americanist approach is fairly simple: It sees society as consisting of nested social structures (Düring, 2013). We can see this approach in The Early Mesoamerican Village, which focused on households only in the first couple of chapters before moving on toward (which can be considered to be neighborhoods in complex sites) and the entire village. Competition and cooperation are horizontal, among households themselves, rather than vertical. Recent European, chiefly British, discussions of Neolithic households often occur within the theoretically charged framework of “social archaeology.” Here, there seems to be greater concern with the vertical relationship between autonomous households and the broader collective of the village community (e.g. Bickle & Kalogiropoulou, 2017, p. 18), with the implication of tension between self-interested households and a cooperative community.

Our view is closer to the Americanist approach as described by Douglass and Gonlin (2012). We see Neolithic households simply as the building blocks of larger social structures. They do not exist in a social vacuum, but we feel that households and larger social structures do not necessarily need to be in conflict. Households may function both autonomously and collectively. For example, at Polgár-Csőszhalom in northeastern Hungary, Faragó (2016) has shown that the stone tool production took place within households, while the procurement of raw material appears to have been communal.

Households of the Brześć Kujawski Group clearly saw benefits in aggregating. These aggregations are more than single sites, and their boundaries are indistinct. It is clear that they lack a high degree of spatial coherence, although at some sites like Osłonki, common areas do appear to have been intentionally left empty (Bogucki & Grygiel, 2017). In addition, despite isotopic evidence for nascent social differentiation (Budd et al., 2020), we cannot say that they had formal leadership above the household level. They are not true villages as one would find in a more complex society with a hierarchy of settlements.

4.1 Hamlets of the Brześć Kujawski Group

We propose to use the term “hamlet” in a very specific sense to describe these aggregations of Neolithic settlement.[10] For this purpose, we are using “hamlet” in the sense introduced by Cancian (1996) to explore this conceptual space, which was then adopted by Bogucki (1999) to describe the role of such agglomerations of settlement in Neolithic societies more generally. In this conception, the hamlet is an institutionalized alliance of domestic groups (i.e. households) that demonstrate affiliation through residential proximity. These households have chosen to be neighbors, and as a result, they have agency in determining their external relationships. The collection of households to which they belong plays a role not only in daily sociality among them but also in their external relationships with households in other such groupings.

Despite being territorially delimited, the hamlet is “socially incomplete” (Cancian, 1996, p. 215) in that its social life extends beyond its edges. Each household has a set of external relations that reach beyond the confines of the local group. Obtaining mates from outside the hamlet would be a primary concern to avoid the potential for “intermarriage gridlock” that Bogucki (1988, p. 121) characterized as a major issue for Neolithic households. In order to avoid this, it would have been necessary to maintain intercommunity ties not based on kinship to facilitate the finding of mates. Moreover, the public life of hamlets is not formally organized. Relations with the outside world are conducted by many different people of all types of social standing. No single individual speaks on behalf of all the component units of the hamlet. Thus, by having a boundary and also outward social relations beyond it, the hamlet was a very important, albeit informal, social form for mediating the external dealings of each household.

In our work over the last 40 years, we have studied what we believe to be two hamlets of the Brześć Kujawski Group. These can be defined on one hand as the Smętowo hamlet, consisting of the sites at Brześć Kujawski and the households at Pikutkowo lying across the eastern arm of Lake Smętowo, and the Osłonki-Miechowice-Konary hamlet (OMK), consisting of Osłonki 1 and 1a on the southern side of two palaeolake basins and Miechowice 4 and 4a and Konary 1 and 1a on the northern side. Despite the intervening bodies of water, interaction between the households within these hamlets would have been fairly straightforward. In fact, the shallow lakes would have been scenes of interaction themselves during fishing, fowling, and turtle catching. To their maximum extent, each hamlet would have contained up to a dozen households at varying points in their developmental cycles.

The inhabitants of the Smętowo and OMK hamlets were probably linked along well-beaten paths and trails and the network of lakes and streams in the postglacial lowland landscape. These hamlets are about 10–12 km apart, so just over a two-hour brisk walk along familiar paths. The Zgłowiączka River is shallow and easily crossed. Assuming friendly interactions and good weather, it would have been possible for an inhabitant of one of these hamlets to visit the other and return home on the same day. It would be interesting to see whether a similar “two-hour rule” can be observed elsewhere in the world of the Brześć Kujawski Group. Reaching out to the world beyond, well-known paths would have led to other such hamlets, such as the nearby households along the Vistula escarpment at Kruszynek and Ludwinowo to the southeast and at Dubielewo and eventually Bodzia to the north (Figure 3). The maps presented by Czerniak (2017, p. 201) indicate that spacing among these sites is fairly consistent, with Ludwinowo-Kruszynek clearly taking on the characteristics of a hamlet as defined here.

Figure 3 
                  Hamlets of the Brześć Kujawski Group around Brześć Kujawski. Key: OS – Osłonki-Miechowice-Konary (OMK) hamlet; BK – Smétowo hamlet centered on Brześć Kujawski and including sites at Pikutkowo and perhaps Smólsk; L – suggested hamlet consisting of longhouses at Ludwinowo sites and Kruszynek; D – suggested hamlet at Dubielewo, possibly extending to Bodzia about 5 km to the north.

Figure 3

Hamlets of the Brześć Kujawski Group around Brześć Kujawski. Key: OS – Osłonki-Miechowice-Konary (OMK) hamlet; BK – Smétowo hamlet centered on Brześć Kujawski and including sites at Pikutkowo and perhaps Smólsk; L – suggested hamlet consisting of longhouses at Ludwinowo sites and Kruszynek; D – suggested hamlet at Dubielewo, possibly extending to Bodzia about 5 km to the north.

Hamlets would have been arenas for competition and alliances among households. They also would have been where factions would have formed among groups of households. In extreme cases, the conflict between factions would have been manifested in violent injuries observed in some skeletons. At the same time, the hamlets would have facilitated cooperation among households, with alliances formed on the basis of marriage and associated institutions such as bridewealth. Given the nested relationships between hamlets and their constituent households noted in the examples given by Cancian, there is no reason to assume the hamlet needed to subsume the households into a larger polity. Each household could continue to interact externally with those in other hamlets just as it would if it was an isolated farmstead.

Composed as they were of individual households, the hamlets of the Brześć Kujawski Group were changing continually on intragenerational and multigenerational time scales. Intragenerational processes included the destruction and rebuilding of individual houses, the digging and filling of the adjacent pits, and the progressive accumulation of burials as household members died and their memorialization in microcemeteries and individual burials. On a multigenerational time scale, the size and spatial extent of the hamlets would have changed. This is seen most clearly at Osłonki, where a large fortification ditch cut through earlier house sites and left others outside the enclosed area, presumably abandoned (Grygiel, 2019). The households at Osłonki had existed first in a nonfortified form, then as a somewhat more densely-settled enclosed arrangement. We can only speculate on the reasons for this, but it presumably involves the development of factions and conflict.

5 Conclusion

In this essay, we have reviewed two key structures of the social organization of the Brześć Kujawski Group, the household and the hamlet. These are nested and complementary, not conflicting. As our knowledge of the Brześć Kujawski Group has increased over the last 40 years, the centrality of the household in imagining the structure of economic and social life on its settlements has never been stronger. However, in 1981, fewer than a dozen sites with longhouses were known, and today, hundreds of houses and their associated features have been recognized on dozens of sites in Kuyavia and beyond. Almost all contain the fundamental elements of the household cluster we identified 40 years ago. Scientific approaches can be fruitfully applied within the framework of the household cluster, such as the pedological analysis of the Brześć Kujawski Group settlement at Żygląd on Chełmno Land (Adamczak, Bednarek, Markiewicz, & Michalski, 2011). Targeted geophysical survey to identify discrete household clusters, such as that carried out at the Linear Pottery and Malice settlement at Targowisko in Małopolska (Golański, Kadrow, & Posselt, 2019), holds considerable promise at sites of the Brześć Kujawski Group.

Through the lens of households, we are able to interpret and understand the social and economic lives of their inhabitants, especially when taking into account that each household has a developmental cycle, as well as to make informed inferences about their spiritual and symbolic behavior. Tringham (2015) has recently highlighted the continued interpretive potential of households for the coming decades, far beyond the original functional interpretations we applied 40 years ago. She writes (2015, p. 222) that household archeology plays, “an essential role in the creation of a multiscalar history that considers such questions as how – in practice – was a sense of place created; how was social memory about this group maintained; what were the myths about garbage; what would the walls of a house say if only they could speak.” Household archeology still has a place in the archeology of the 21st century.

At the same time, we need to recognize that households did not exist in isolation. Their aggregations are best interpreted using Cancian’s term “hamlet” for affiliated households engaging independently in interactions with other households and with other such groupings, which lack a formal structure to speak on their behalf. Looking at hamlets composed of discrete households can provide insight into many different processes, including landscape development and the emergence of social inequalities. Looking forward, we predict that the hamlet model of household aggregation will provide a framework in which to interpret isotopic and DNA evidence as it becomes available from the many burials of the Brześć Kujawski Group. Combining lines of new evidence within the household-hamlet nested structure should lead to fruitful interpretations of the development of Neolithic society.

What is New in the Neolithic?– A Special Issue Dedicated to Lech Czerniak, edited by Joanna Pyzel, Katarzyna Inga Michalak & Marek Z. Barański.

  1. Conflict of interest: Authors state no conflict of interest.


Adamczak, K., Bednarek, R., Markiewicz, M., & Michalski, A. (2011). Settlement organization and activity of the Neolithic community of the post-LBK culture in Żygląd on Chełmno Land. Archeological and pedological investigations. In I. Hildebrandt-Radke, W. Dörfler, J. Czebreszuk, & J. Müller (Eds.), Anthropogenic pressure in the Neolithic and Bronze Age on the Central European lowlands (pp. 113–118). Poznan: Bogucki Wydawnictwo Naukowe.Search in Google Scholar

Bickle, P., & Kalogiropoulou, E. (2017). “Very like the Neolithic”: The everyday and settlement in the European Neolithic. In P. Bickle, V. Cummings, D. Hofmann, & J. Pollard (Eds.), The Neolithic of Europe: Papers in honour of Alasdair Whittle (pp. 7–23). Oxford: Oxbow Books.10.2307/j.ctvh1dgtm.8Search in Google Scholar

Blake, M., & Clark, J. E. (1999). The emergence of hereditary inequality: The case of Pacific coastal Chiapas, Mexico. In M. Blake (Ed.), Pacific Latin America in prehistory: The evolution of archaic and formative cultures (pp. 55–73). Pullman, Washington: Washington State University Press.Search in Google Scholar

Boelicke, U. (1982). Gruben und Häuser: Untersuchungen zue Struktur bandkeramischer Hofplätze. In J. Pavúk (Ed.), Siedlungen der Kultur mit linearbandkeramik in Europea (pp. 17–28). Nitra: Archaeological Institute of the Slovakian Academy of Science.Search in Google Scholar

Bogucki, P. (1988). Forest farmers and stockherders: Early agriculture and its consequences in North-Central Europe. Cambridge: Cambridge University Press.Search in Google Scholar

Bogucki, P. (1999). The origins of human society. Oxford: Blackwell Publishers.Search in Google Scholar

Bogucki, P. (2003). A Neolithic tribal society in northern Poland. In W. Parkinson (Ed.), The archaeology of tribal societies, (pp. 372–383). Ann Arbor: International Monographs in Prehistory.10.2307/j.ctv8bt29z.20Search in Google Scholar

Bogucki, P. (2014). Planning for the past in Neolithic central Europe. In J. Osborne (Ed.), Approaching monumentality in archaeology (pp. 217–232). Albany: State University of New York Press.Search in Google Scholar

Bogucki, P., & Grygiel, R. (1981). The household cluster at Brześć Kujawski 3: Small-site methodology in the Polish lowlands. World Archaeology, 13(1), 59–72. doi: 10.1080/00438243.1981.9979814.Search in Google Scholar

Bogucki, P., & Grygiel, R. (2017). Neolithic residential landscapes in central Europe. In A. Marciniak-Kajzer, A. Andrzejewski, A. Golański, R. Seweryn, & M. Wąs (Eds.), Nie tylko krzemienie: Studia ofiarowane prof. Lucynie Domańskiej w 45-lecie pracy naukowo-dydaktycznej i w 70. rocznicę urodzin (pp. 281–294). Łódź: Uniwersytet Łódzki.Search in Google Scholar

Budd, C., Bogucki, P., Lillie, M., Grygiel, R., Lorkiewicz, W., & Schulting, R. (2020). All things bright: Copper grave goods and diet at the Neolithic site of Osłonki, Poland. Antiquity, 94(376), 932–947.10.15184/aqy.2020.102Search in Google Scholar

Cancian, F. (1996). The hamlet as mediator. Ethnology, 35(3), 215–228.10.2307/3773920Search in Google Scholar

Chang, K.-C. (1958). Study of the Neolithic social grouping: Examples from the new world. American Anthropologist, 60(2), 298–334.10.1525/aa.1958.60.2.02a00080Search in Google Scholar

Clark, G. (1952). Prehistoric Europe; The economic basis. London: Methuen.Search in Google Scholar

Czerniak, L. (1979). Osada kultury lendzielskiej w Kościelcu Kujawskim, Gm. Pakość, Stan. 16. Pomerania Antiqua, 8, 73–109.Search in Google Scholar

Czerniak, L. (1980). Rozwój społeczeństw kultury póżnej ceramiki wstęgowej na Kujawach. Poznań: Wydawnictwo Naukowe Uniwersytetu im. Adama Mickiewicza.Search in Google Scholar

Czerniak, L. (2002). Settlements of the Brześć Kujawski type on the Polish Lowlands. Archeologické Rozhledy, 54(1), 9–22.Search in Google Scholar

Czerniak, L. (2017). Zanim powstała kultura brzesko-kujawska. Przykład stanowisk 2, 3, 6 i 7 w Ludwinowie, gm. Włocławek. In A. Marciniak-Kajzer, A. Andrzejewski, A. Golański, R. Seweryn, & M. Wąs (Eds.), Nie tylko krzemienie: Studia ofiarowane prof. Lucynie Domańskiej w 45-lecie pracy naukowo-dydaktycznej i w 70. rocznicę urodzin (pp. 199–236). Łódź: Uniwersytet Łódzki.Search in Google Scholar

Czerniak, L., & Pyzel, J. (2016). Being at Home in the Early Chalcolithic. The Longhouse Phenomenon in the Brześć Kujawski Culture in the Polish Lowlands. Open Archaeology, 2(1), 97–114. doi: 10.1515/opar-2016-0007.Search in Google Scholar

Douglass, J. G., & Gonlin, N. (2012). The household as analytical unit. In J. G. Douglass & N. Gonlin (Eds.), Ancient households of the Americas (pp. 1–44). Boulder: University Press of Colorado.Search in Google Scholar

Düring, B. S. (2013). The anatomy of a prehistoric community: Reconsidering Çatalhöyük. In J. Birch (Ed.), From Prehistoric villages to cities (pp. 37–57). New York: Routledge.Search in Google Scholar

Faragó, N. (2016). Houses, households, activity zones in the post-LBK World. Results of the raw material analysis of the chipped stone tools at Polgár-Csöszhalom, Northeast Hungary. Open Archaeology, 2, 346–367.10.1515/opar-2016-0024Search in Google Scholar

Flannery, K. V. (Ed.). (1976). The early mesoamerican village. New York: Academic Press.Search in Google Scholar

Fortes, M. (1958). Introduction. In J. Goody (Ed.), The developmental cycle in domestic groups (pp. 1–14). Cambridge: Cambridge University Press.10.7312/gell92894-003Search in Google Scholar

Füzesi, A., & Raczky, P. (2018). Öcsöd-Kováshalom. Potscape of a Late Neolithic site in the Tisza region. Dissertationes Archaeologicae, 3(6), 43–146. doi: 10.17204/dissarch.2018.43.Search in Google Scholar

Gallant, T. (1991). Risk and survival in ancient Greece: Reconstructing the rural domestic economy. Stanford: Stanford University Press.Search in Google Scholar

Golański, A., Kadrow, S., & Posselt, M. (2019). Geomagnetic prospection of an Early-Neolithic settlement complex in Targowisko, Małopolskie Voivodeship. RAPORT, 14, 7–20.Search in Google Scholar

Grygiel, R. (1986). The household cluster as a fundamental social unit of the Brześć Kujawski group of the Lengyel culture. Prace i Materiały Muzeum Archeologicznego i Etnograficznego w Łodzi, 31(1984), 43–334.Search in Google Scholar

Grygiel, R. (1994). Untersuchungen zur Gesellschaftsorganisation des Früh- und Mittelneolithikums in Mitteleuropa. In P. Koštuřík (Ed.), Internationales Symposium über die Lengyel-Kultur: 1880–1988; Znojmo-Kravsko-Těšetice 3.-7.10.1988 (pp. 43–77). Brno, Łódź: Filozofická Fakulta Masarykovy Univerzity/Muzeum Archeologiczne i Etnograficzne.Search in Google Scholar

Grygiel, R. (2008). Neolit i Początki Epoki Brązu w Rejonie Brześcia Kujawskiego i Osłonek (The Neolithic and Early Bronze Age in the Brześć Kujawski and Osłonki Region), Volume II. Łódź: Konrad Jażdżewski Foundation for Archaeological Research, Museum of Archaeology and Ethnography.Search in Google Scholar

Grygiel, R. (2019). Uwagi na temat rozwoju społeczeństw środkowoneolitycznych w rejonie Brześcia Kujawskiego i Osłonek. In M. Szmyt, P. Chachlikowski, J. Czebreszuk, M. Ignaczak, & P. Makarowicz (Eds.), VIR BIMARIS. Od kujawskiego matecznika do stepów nadczarnomorskich. Studia z dziejów międzymorza bałtycko-pontyjskiego ofiarowane Profesorowi Aleksandrowi Kośko (pp. 89–100). Poznań: Adam Mickiewicz University, Institute of Archaeololgy, Department of East-Central European Prehistory.Search in Google Scholar

Grygiel, R., & Bogucki, P. (1997). Early farmers in north-central Europe: 1989–1994 excavations at Oslonki, Poland. Journal of Field Archaeology, 24(2), 161–178.Search in Google Scholar

Hirth, K. (2009). Craft production, household diversification, and domestic economy in Prehispanic Mesoamerica. Archaeological Papers of the American Anthropological Association, 19(1), 13–32. doi: 10.1111/j.1551-8248.2009.01010.x.Search in Google Scholar

Jażdżewski, K. (1938). Cmentarzyska kultury ceramiki wstęgowej i związane z nimi ślady osadnictwa w Brześciu Kujawskim. Wiadomości Archeologiczne, 15, 1–105.Search in Google Scholar

Kabaciński, J., Sobkowiak-Tabaka, I., David, É., Osypińska, M., Terberger, T., & Winiarska-Kabacińska, M. (2014). The chronology of T-shaped axes in the Polish Lowland. Sprawozdania Archeologiczne, 66, 29–56.Search in Google Scholar

Lightfoot, R. (1994). The Duckfoot site, Volume 2: Archaeology of the house and household. Cortes, Colorado: Crow Canyon Archaeological Center.Search in Google Scholar

Lorkiewicz, W. (2012). Skeletal trauma and violence among the early farmers of the North European Plain: Evidence from Neolithic settlements of the Lengyel Culture in Kuyavia, north-central Poland. In R. Schulting & L. Fibiger (Eds.), Sticks, Stones, and Broken Bones: Neolithic Violence in a European Perspective (pp. 51–76). Oxford: Oxford University Press.10.1093/acprof:osobl/9780199573066.003.0004Search in Google Scholar

Lorkiewicz, W., Płoszaj, T., Jędrychowska-Dańska, K., Żądzińska, E., Strapagiel, D., Haduch, E. (2015). Between the Baltic and Danubian worlds: The genetic affinities of a middle neolithic population from Central Poland. PloS One, 10(2), e0118316.10.1371/journal.pone.0118316Search in Google Scholar

Lüning, J. (1982). Research into the Bandkeramik settlement of the Aldenhovener Platte in the Rhineland. Analecta Praehistorica Leidensia, 15, 1–29.Search in Google Scholar

Maciejewski, F. (1956). Budowla trapezowata kultury nadcisańskiej z Biskupina. Sprawozdania Archeologiczne, 2, 26–33.Search in Google Scholar

Moseley, M. E., & Mackey, C. J. (1972). Peruvian settlement pattern studies and small site methodology. American Antiquity, 37(1), 67–81.10.2307/278886Search in Google Scholar

Scarre, C. (2004). Review of Les pratiques funéraires néolithiques avant 3500 av. J.-C. en France et dans les régions limitrophes. Table ronde SPF, Saint-Germain-en-Laye 15-17 juin 2001, edited by Philippe Chambon and Jean LeClerc, Mémoire XXXIII de la Société Préhistorique Française. Société Préhistorique Française, Paris, 2003. Book Reviews, The Prehistoric Society. in Google Scholar

Tringham, R. (1983). The development of the household as the primary unit of production in Neolithic and Eneolithic South-east Europe. Paper presented at the 48th annual meeting of the Society for American Archaeology, Pittsburgh, PA.Search in Google Scholar

Tringham, R. (2015). Household archaeology. In J. D. Wright (Ed.), International encyclopedia of the social & behavioral sciences (2nd ed., pp. 219–223). Oxford: Elsevier.Search in Google Scholar

Tringham, R., Brukner, B., & Voytek, B. (1985). The Opovo project: A study of socioeconomic change in the Balkan Neolithic. Journal of Field Archaeology, 12(4), 425–444.Search in Google Scholar

Tringham, R., & Krstić, D. (1990). Conclusion: Selevac in the wider context of European prehistory. In R. Tringham & D. Krstić (Eds.), Selevac: A Neolithic village in Yugoslavia (pp. 567–616). Los Angeles: Cotsen Institute of Archaeology, University of California at Los Angeles.Search in Google Scholar

Wilk, R. R., & Netting, R. M. (1984). Households: Changing forms and functions. In R. M. Netting, R. R. Wilk, & E. J. Arnould (Eds.), Households: Comparative and historical studies of the domestic group (pp. 1–28). Berkeley: University of California Press.10.1525/9780520322943-004Search in Google Scholar

Wilk, R. R., & Rathje, W. L. (Eds.). (1982). Archaeology of the household: Building a prehistory of domestic life (Vol. 25). Beverly Hills, California: Sage Publications.Search in Google Scholar

Winter, M. (1976). The archaeological household cluster in the Valley of Oaxaca. In K. V. Flannery (Ed.), The Early Mesoamerican village (pp. 25–31). New York: Academic Press.Search in Google Scholar

Received: 2021-01-29
Revised: 2021-12-02
Accepted: 2021-12-15
Published Online: 2022-06-17

© 2022 Peter Bogucki and Ryszard Grygiel, published by De Gruyter

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