MLA

Steinberg, Saul, 1914-1999. Untitled [Collage with drawing, photograph, and newspaper clipping; cartoon words]. Box 432, folder 5906. undated. https://collections.library.yale.edu/catalog/33073460.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 432, folder 5906"])(undated)[Untitled [Collage with drawing, photograph, and newspaper clipping; cartoon words]]. https://collections.library.yale.edu/catalog/33073460.