Cite

City of Baltimore topographical survey / made under the direction of H.T. Douglas, chief engineer.

MLA

City of Baltimore Topographical Survey / Made under the Direction of H.T. Douglas, Chief Engineer. Photo-Lith. by A. Hoen, 1896. https://collections.library.yale.edu/catalog/15811185.

APA, 6th edition

City of Baltimore topographical survey / made under the direction of H.T. Douglas, chief engineer. (1896). [Maps]. Photo-Lith. by A. Hoen, https://collections.library.yale.edu/catalog/15811185.