MLA

Wilder, Thornton, 1897-1975. Various 1960 pictures. Box 151, folder 3646. n.d.. https://collections.library.yale.edu/catalog/16587325.

APA, 6th edition

Wilder, Thornton, 1897-1975. (["Box 151, folder 3646"])(n.d.)[Various 1960 pictures]. https://collections.library.yale.edu/catalog/16587325.