MLA

Steinberg, Saul, 1914-1999. Untitled [Mirage]. Box 79, folder 1646. undated. https://collections.library.yale.edu/catalog/32471763.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 79, folder 1646"])(undated)[Untitled [Mirage]]. https://collections.library.yale.edu/catalog/32471763.