MLA

Service, International Film. Mexican Federal Artillery Signal Corps Stationed Four Miles from Vera Cruz. 0AD. https://collections.library.yale.edu/catalog/2017127.

APA, 6th edition

Service, I. F. (0 C.E.). Mexican federal artillery signal corps stationed four miles from Vera Cruz. [Photographic postcards, Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2017127.