MLA

Van Vechten, Carl, 1880-1964. Hull, Elizabeth Shaffer. Box 354, folder 4777. 1934 October 18. https://collections.library.yale.edu/catalog/2047338.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 354, folder 4777"])(1934 October 18)[Hull, Elizabeth Shaffer]. https://collections.library.yale.edu/catalog/2047338.