MLA

Van Vechten, Carl, 1880-1964. Lovett, Robert Morss. Box 362, folder 5002. 1932 December 21. https://collections.library.yale.edu/catalog/2056536.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 362, folder 5002"])(1932 December 21)[Lovett, Robert Morss]. https://collections.library.yale.edu/catalog/2056536.