"Frequenz", 31.2 (1977): 37-64. Retrieved 19 Jun. 2013, from http://www.degruyter.com/view/j/freq.1977.31.2/issue-files/freq.1977.31.2.xml

Frequenz (1977), 31(2), pp. 37-64. Retrieved 19 Jun. 2013, from http://www.degruyter.com/view/j/freq.1977.31.2/issue-files/freq.1977.31.2.xml

Frequenz. 1977. 31(2): 37-64. Retrieved 19 Jun. 2013, from http://www.degruyter.com/view/j/freq.1977.31.2/issue-files/freq.1977.31.2.xml