Wisconsin, Milwaukee special map / Henry Gannett, chief topographer...

Chicago citation style
Geological Survey (U.S.). Wisconsin, Milwaukee special map / Henry Gannett, chief topographer.... 1906. Retrieved from the Digital Public Library of America, http://collections.lib.uwm.edu/cdm/ref/collection/agdm/id/2049. (Accessed December 5, 2019.)
APA citation style
Geological Survey (U.S.), (1906) Wisconsin, Milwaukee special map / Henry Gannett, chief topographer.... Retrieved from the Digital Public Library of America, http://collections.lib.uwm.edu/cdm/ref/collection/agdm/id/2049
MLA citation style
Geological Survey (U.S.). Retrieved from the Digital Public Library of America <http://collections.lib.uwm.edu/cdm/ref/collection/agdm/id/2049>.
Note: These citations are programmatically generated and may be incomplete.