Cite

[Photograph of man leading a horse up a steep slope]

MLA

[Photograph of Man Leading a Horse up a Steep Slope]. 1915. https://collections.library.yale.edu/catalog/11683447.

APA, 6th edition

[Photograph of man leading a horse up a steep slope]. (1915). [Photographs, Slides (glass)]. https://collections.library.yale.edu/catalog/11683447.