MLA

Steinberg, Saul, 1914-1999. Untitled [Rainbow reflection]. Box 80, folder 1757. circa 1974. https://collections.library.yale.edu/catalog/16856324.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 80, folder 1757"])(circa 1974)[Untitled [Rainbow reflection]]. https://collections.library.yale.edu/catalog/16856324.