Habermann, Norbert, Günter Weick and Herbert Roth. §§ 21-79. (Allgemeiner Teil 2). Berlin, Boston: Sellier - de Gruyter, 2005. Web. Retrieved 25 May. 2013, from http://www.degruyter.com/view/product/19947

Habermann, N., Weick, G. & Roth, H. (2005). §§ 21-79. (Allgemeiner Teil 2). Berlin, Boston: Sellier - de Gruyter. Retrieved 25 May. 2013, from http://www.degruyter.com/view/product/19947

Habermann, Norbert, Günter Weick and Herbert Roth. 2005. §§ 21-79. (Allgemeiner Teil 2). Berlin, Boston: Sellier - de Gruyter. Retrieved 25 May. 2013, from http://www.degruyter.com/view/product/19947