MLA

Section, Great Britain. War Office. General Staff. Geographical. Nanking [Cartographic Material]. Army Map Service, 1945. https://collections.library.yale.edu/catalog/15510603.

APA, 6th edition

Section, G. B. W. O. G. S. G. (1945). Nanking [cartographic material]. [Maps]. Army Map Service, https://collections.library.yale.edu/catalog/15510603.