Ruby

Chicago citation style
Geological Survey (U.S. Ruby. 1973. Retrieved from the Digital Public Library of America, http://content.wisconsinhistory.org/cdm/ref/collection/maps/id/2916. (Accessed February 27, 2020.)
APA citation style
Geological Survey (U.S, (1973) Ruby. Retrieved from the Digital Public Library of America, http://content.wisconsinhistory.org/cdm/ref/collection/maps/id/2916
MLA citation style
Geological Survey (U.S. Retrieved from the Digital Public Library of America <http://content.wisconsinhistory.org/cdm/ref/collection/maps/id/2916>.
Note: These citations are programmatically generated and may be incomplete.