Ernst Haeckel

Chicago citation style
Ernst Haeckel. 1875 (?). Retrieved from the Digital Public Library of America, http://contentdm.acpl.lib.in.us/cdm/ref/collection/p15155coll1/id/2847. (Accessed July 18, 2018.)
APA citation style
(1875 (?)) Ernst Haeckel. Retrieved from the Digital Public Library of America, http://contentdm.acpl.lib.in.us/cdm/ref/collection/p15155coll1/id/2847
MLA citation style
Retrieved from the Digital Public Library of America <http://contentdm.acpl.lib.in.us/cdm/ref/collection/p15155coll1/id/2847>.
Note: These citations are programmatically generated and may be incomplete.