"1. Allgemeine Metaphysik" J. F. Herbart. Berlin, Boston: DE GRUYTER, 1909. 74-92. Web. Retrieved 25 May. 2013, from http://www.degruyter.com/view/books/9783111598277/9783111598277.74/9783111598277.74.xml

1. Allgemeine Metaphysik (1909). J. F. Herbart (pp. 74-92). Berlin, Boston: DE GRUYTER. Retrieved 25 May. 2013, from http://www.degruyter.com/view/books/9783111598277/9783111598277.74/9783111598277.74.xml

1. Allgemeine Metaphysik. 1909. In J. F. Herbart, 74-92. Berlin, Boston: DE GRUYTER. Retrieved 25 May. 2013, from http://www.degruyter.com/view/books/9783111598277/9783111598277.74/9783111598277.74.xml