MLA

Steinberg, Saul, 1914-1999. Untitled [Woman on seesaw]. Box 454, folder 6273. undated. https://collections.library.yale.edu/catalog/16851462.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 454, folder 6273"])(undated)[Untitled [Woman on seesaw]]. https://collections.library.yale.edu/catalog/16851462.