MLA

Service, United States. Army Map. Barcelona [Cartographic Material] : City Plan. Army Map Service, U.S. Army, 1943. https://collections.library.yale.edu/catalog/15487278.

APA, 6th edition

Service, U. S. A. M. (1943). Barcelona [cartographic material] : city plan. [Maps]. Army Map Service, U.S. Army, https://collections.library.yale.edu/catalog/15487278.