"Frequenz", 17.1 (1963): 1-40. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/freq.1963.17.1/issue-files/freq.1963.17.1.xml

Frequenz (1963), 17(1), pp. 1-40. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/freq.1963.17.1/issue-files/freq.1963.17.1.xml

Frequenz. 1963. 17(1): 1-40. Retrieved 21 May. 2013, from http://www.degruyter.com/view/j/freq.1963.17.1/issue-files/freq.1963.17.1.xml