Cite

[Photograph of Thornton Wilder standing with sister (on horseback) and mother]

MLA

[Photograph of Thornton Wilder Standing with Sister (on Horseback) and Mother]. 1928. https://collections.library.yale.edu/catalog/2040399.

APA, 6th edition

[Photograph of Thornton Wilder standing with sister (on horseback) and mother]. (1928). [Group portraits, Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2040399.