MLA

Van Vechten, Carl, 1880-1964. Mailer, Norman. Box 363, folder 5033. 1948 September 13. https://collections.library.yale.edu/catalog/2065557.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 363, folder 5033"])(1948 September 13)[Mailer, Norman]. https://collections.library.yale.edu/catalog/2065557.