MLA

Section, Great Britain. War Office. General Staff. Geographical. Ibiza & Formentera [Cartographic Material]. Army Map Service, U.S. Army, 1943. https://collections.library.yale.edu/catalog/15487355.

APA, 6th edition

Section, G. B. W. O. G. S. G. (1943). Ibiza & Formentera [cartographic material]. [Maps]. Army Map Service, U.S. Army, https://collections.library.yale.edu/catalog/15487355.