MLA

Division, United States. War Dept. General Staff. War College. Map of Liberia / Prepared in the War College Division, General Staff ; W.J. Jacobi, Draftsman. The Division, 1916. https://collections.library.yale.edu/catalog/15533581.

APA, 6th edition

Division, U. S. W. D. G. S. W. C. (1916). Map of Liberia / prepared in the War College Division, General Staff ; W.J. Jacobi, draftsman. [Maps]. The Division, https://collections.library.yale.edu/catalog/15533581.