"Frequenz", 43.10 (1989): 257-284. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/freq.1989.43.10/issue-files/freq.1989.43.10.xml

Frequenz (1989), 43(10), pp. 257-284. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/freq.1989.43.10/issue-files/freq.1989.43.10.xml

Frequenz. 1989. 43(10): 257-284. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/freq.1989.43.10/issue-files/freq.1989.43.10.xml