"Forum Mathematicum", 4.Jahresband (1992): 1-633. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/form.1992.issue-4/issue-files/form.1992.issue-4.xml

Forum Mathematicum (1992), 4(Jahresband), pp. 1-633. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/form.1992.issue-4/issue-files/form.1992.issue-4.xml

Forum Mathematicum. 1992. 4(Jahresband): 1-633. Retrieved 20 May. 2013, from http://www.degruyter.com/view/j/form.1992.issue-4/issue-files/form.1992.issue-4.xml