MLA

Van Vechten, Carl, 1880-1964. Van Vechten, Carl. Box 379, folder 5549. 1932 May 20. https://collections.library.yale.edu/catalog/10589836.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 379, folder 5549"])(1932 May 20)[Van Vechten, Carl]. https://collections.library.yale.edu/catalog/10589836.