These are duck eggs

Chicago citation style
These are duck eggs. 1987-1990. Retrieved from the Digital Public Library of America, http://ark.digitalcommonwealth.org/ark:/50959/1n79h4320. (Accessed July 17, 2018.)
APA citation style
(1987-1990) These are duck eggs. Retrieved from the Digital Public Library of America, http://ark.digitalcommonwealth.org/ark:/50959/1n79h4320
MLA citation style
Retrieved from the Digital Public Library of America <http://ark.digitalcommonwealth.org/ark:/50959/1n79h4320>.
Note: These citations are programmatically generated and may be incomplete.