MLA

Division, United States. Adjutant-General's Office. Military Information. Sketch Showing Movements and Positions of Troops in the Affair of August 9th 1898 at Coamo, Puerto Rico : August 21, 1898, Scale 1000' to 1' / Sergt. S.H. Knight, Topographer. Norris Peters Co. Photo-litho, 0AD. https://collections.library.yale.edu/catalog/15832256.

APA, 6th edition

Division, U. S. A.-G. O. M. I. (0 C.E.). Sketch showing movements and positions of troops in the affair of August 9th 1898 at Coamo, Puerto Rico : August 21, 1898, scale 1000' to 1' / Sergt. S.H. Knight, topographer. [Maps]. Norris Peters Co. Photo-litho, https://collections.library.yale.edu/catalog/15832256.