MLA

Van Vechten, Carl, 1880-1964. Hersey, John. Box 353, folder 4750. 1958 March 4. https://collections.library.yale.edu/catalog/2047013.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 353, folder 4750"])(1958 March 4)[Hersey, John]. https://collections.library.yale.edu/catalog/2047013.