"Das Rechenzentrum", 2.3 (1979): 127-184. Retrieved 23 May. 2013, from http://www.degruyter.com/view/j/piko.1.1979.2.issue-3/issue-files/piko.1.1979.2.issue-3.xml

Das Rechenzentrum (1979), 2(3), pp. 127-184. Retrieved 23 May. 2013, from http://www.degruyter.com/view/j/piko.1.1979.2.issue-3/issue-files/piko.1.1979.2.issue-3.xml

Das Rechenzentrum. 1979. 2(3): 127-184. Retrieved 23 May. 2013, from http://www.degruyter.com/view/j/piko.1.1979.2.issue-3/issue-files/piko.1.1979.2.issue-3.xml