MLA

Kuh, Katharine, 1904-1994. Duchamp, Marcel. Box 1, folder 7. 1948-61, n.d.. https://collections.library.yale.edu/catalog/17059897.

APA, 6th edition

Kuh, Katharine, 1904-1994. (["Box 1, folder 7"])(1948-61, n.d.)[Duchamp, Marcel]. https://collections.library.yale.edu/catalog/17059897.