MLA

Steinberg, Saul, 1914-1999. Untitled [Woman holding cat]. Box 78, folder 1587. undated. https://collections.library.yale.edu/catalog/32457466.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 78, folder 1587"])(undated)[Untitled [Woman holding cat]]. https://collections.library.yale.edu/catalog/32457466.