"Das Rechenzentrum", 4.3 (1981): 135-196. Retrieved 24 May. 2013, from http://www.degruyter.com/view/j/piko.1.1981.4.issue-3/issue-files/piko.1.1981.4.issue-3.xml

Das Rechenzentrum (1981), 4(3), pp. 135-196. Retrieved 24 May. 2013, from http://www.degruyter.com/view/j/piko.1.1981.4.issue-3/issue-files/piko.1.1981.4.issue-3.xml

Das Rechenzentrum. 1981. 4(3): 135-196. Retrieved 24 May. 2013, from http://www.degruyter.com/view/j/piko.1.1981.4.issue-3/issue-files/piko.1.1981.4.issue-3.xml