MLA

Stein, Gertrude, 1874-1946. Man Ray. Box 152, folder 3677-3681. 1920. https://collections.library.yale.edu/catalog/2003468.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 152, folder 3677-3681"])(1920)[Man Ray]. https://collections.library.yale.edu/catalog/2003468.