MLA

Section, Great Britain. War Office. General Staff. Geographical. Lower Mesopotamia, between Baghdad and the Persian Gulf [Cartographic Material]. War Office of the Geographical Section, General Staff, 1919. https://collections.library.yale.edu/catalog/15827189.

APA, 6th edition

Section, G. B. W. O. G. S. G. (1919). Lower Mesopotamia, between Baghdad and the Persian Gulf [cartographic material]. [Maps]. War Office of the Geographical Section, General Staff, https://collections.library.yale.edu/catalog/15827189.