MLA

Van Vechten, Carl, 1880-1964. Gibson, Althea. Box 91, folder 1575. 1958 November 20. https://collections.library.yale.edu/catalog/2001902.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 91, folder 1575"])(1958 November 20)[Gibson, Althea]. https://collections.library.yale.edu/catalog/2001902.