Cite

[No. 109: Photograph of horses with man on grassy slope]

MLA

[No. 109: Photograph of Horses with Man on Grassy Slope]. 1915. https://collections.library.yale.edu/catalog/11680831.

APA, 6th edition

[No. 109: Photograph of horses with man on grassy slope]. (1915). [Photographs, Slides (glass)]. https://collections.library.yale.edu/catalog/11680831.