MLA

Van Vechten, Carl, 1880-1964. Angus, Donald. Box 332, folder 4135. 1932 March 26. https://collections.library.yale.edu/catalog/2030012.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 332, folder 4135"])(1932 March 26)[Angus, Donald]. https://collections.library.yale.edu/catalog/2030012.