MLA

Simpson, Kenneth F. (Kenneth Farrand), 1895-1941. Photographs, undated. Box 36, folder 40. undated. https://collections.library.yale.edu/catalog/10021434.

APA, 6th edition

Simpson, Kenneth F. (Kenneth Farrand), 1895-1941. (["Box 36, folder 40"])(undated)[Photographs, undated]. https://collections.library.yale.edu/catalog/10021434.