"Frequenz", 26.5 (1972): 117-154. Retrieved 25 May. 2013, from http://www.degruyter.com/view/j/freq.1972.26.5/issue-files/freq.1972.26.5.xml

Frequenz (1972), 26(5), pp. 117-154. Retrieved 25 May. 2013, from http://www.degruyter.com/view/j/freq.1972.26.5/issue-files/freq.1972.26.5.xml

Frequenz. 1972. 26(5): 117-154. Retrieved 25 May. 2013, from http://www.degruyter.com/view/j/freq.1972.26.5/issue-files/freq.1972.26.5.xml