"Frequenz", 26.7 (1972): 189-214. Retrieved 20 Jun. 2013, from http://www.degruyter.com/view/j/freq.1972.26.7/issue-files/freq.1972.26.7.xml

Frequenz (1972), 26(7), pp. 189-214. Retrieved 20 Jun. 2013, from http://www.degruyter.com/view/j/freq.1972.26.7/issue-files/freq.1972.26.7.xml

Frequenz. 1972. 26(7): 189-214. Retrieved 20 Jun. 2013, from http://www.degruyter.com/view/j/freq.1972.26.7/issue-files/freq.1972.26.7.xml