MLA

Van Vechten, Carl, 1880-1964. Baldwin, James. Box 114, folder 2171. 1955 September 13. https://collections.library.yale.edu/catalog/33297778.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 114, folder 2171"])(1955 September 13)[Baldwin, James]. https://collections.library.yale.edu/catalog/33297778.