MLA

Steinberg, Saul, 1914-1999. Untitled [Woman reclining]. Box 78, folder 1593. undated. https://collections.library.yale.edu/catalog/32457484.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 78, folder 1593"])(undated)[Untitled [Woman reclining]]. https://collections.library.yale.edu/catalog/32457484.