Cite

[No. 32: Photograph of horses in field of flowers]

MLA

[No. 32: Photograph of Horses in Field of Flowers]. 1915. https://collections.library.yale.edu/catalog/11679632.

APA, 6th edition

[No. 32: Photograph of horses in field of flowers]. (1915). [Photographs, Slides (glass)]. https://collections.library.yale.edu/catalog/11679632.