"Frequenz", 29.6 (1975): 157-190. Retrieved 22 May. 2013, from http://www.degruyter.com/view/j/freq.1975.29.6/issue-files/freq.1975.29.6.xml

Frequenz (1975), 29(6), pp. 157-190. Retrieved 22 May. 2013, from http://www.degruyter.com/view/j/freq.1975.29.6/issue-files/freq.1975.29.6.xml

Frequenz. 1975. 29(6): 157-190. Retrieved 22 May. 2013, from http://www.degruyter.com/view/j/freq.1975.29.6/issue-files/freq.1975.29.6.xml