MLA

Service, United States. Army Map. Belfort [Cartographic Material] : City Plan / Prepared under the Direction of the Chief of Engineers, U.S. Army. Army Map Service, 1943. https://collections.library.yale.edu/catalog/15484344.

APA, 6th edition

Service, U. S. A. M. (1943). Belfort [cartographic material] : city plan / prepared under the direction of the Chief of Engineers, U.S. Army. [Maps]. Army Map Service, https://collections.library.yale.edu/catalog/15484344.