MLA

Section, Great Britain. War Office. General Staff. Geographical. Pantelleria [Cartographic Material] / Drawn by GSGS, War Office 1940. Army Map Service, U.S. Army, 1943. https://collections.library.yale.edu/catalog/15491925.

APA, 6th edition

Section, G. B. W. O. G. S. G. (1943). Pantelleria [cartographic material] / drawn by GSGS, War Office 1940. [Topographic maps]. Army Map Service, U.S. Army, https://collections.library.yale.edu/catalog/15491925.