MLA

Steinberg, Saul, 1914-1999. Untitled [Woman reclining]. Box 454, folder 6274. undated. https://collections.library.yale.edu/catalog/16851463.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 454, folder 6274"])(undated)[Untitled [Woman reclining]]. https://collections.library.yale.edu/catalog/16851463.