MLA

Steinberg, Saul, 1914-1999. Untitled [Landscape]. Box 78, folder 1535. undated. https://collections.library.yale.edu/catalog/32457109.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 78, folder 1535"])(undated)[Untitled [Landscape]]. https://collections.library.yale.edu/catalog/32457109.