MLA

Section, Great Britain. War Office. General Staff. Geographical. The Anglo-Egyptian Sudan [Cartographic Material]. G.S.G.S., 1928. https://collections.library.yale.edu/catalog/15532716.

APA, 6th edition

Section, G. B. W. O. G. S. G. (1928). The Anglo-Egyptian Sudan [cartographic material]. [Maps]. G.S.G.S., https://collections.library.yale.edu/catalog/15532716.