MLA

Division, United States. Adjutant-General's Office. Military Information. Sketch Map of Guayama and Vicinity Showing Location of Spanish Strongholds, and Route of March Made by Brig. Gen. Hains on Aug 13, 1898. Norris Peters Co. Photo-litho, 0AD. https://collections.library.yale.edu/catalog/15874738.

APA, 6th edition

Division, U. S. A.-G. O. M. I. (0 C.E.). Sketch map of Guayama and vicinity showing location of Spanish strongholds, and route of March made by Brig. Gen. Hains on Aug 13, 1898. [Maps]. Norris Peters Co. Photo-litho, https://collections.library.yale.edu/catalog/15874738.