MLA

Van Vechten, Carl, 1880-1964. Dufty, William. Box 346 | Folder 4529. 1960 May 17. https://collections.library.yale.edu/catalog/2033560.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 346 | Folder 4529"])(1960 May 17)[Dufty, William]. https://collections.library.yale.edu/catalog/2033560.