Mathematische Unterhaltungen und Spiele

Chicago citation style
Ahrens, W. (Wilhelm), 1872-1927. Mathematische Unterhaltungen und Spiele. 1921, '18. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/000586258. (Accessed December 19, 2018.)
APA citation style
Ahrens, W. (Wilhelm), 1872-1927, (1921, '18) Mathematische Unterhaltungen und Spiele. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/000586258
MLA citation style
Ahrens, W. (Wilhelm), 1872-1927. Retrieved from the Digital Public Library of America <http://catalog.hathitrust.org/Record/000586258>.
Note: These citations are programmatically generated and may be incomplete.