MLA

Van Vechten, Carl, 1880-1964. March, Fredric. Box 385 | Folder 5806. 1939 May 28. https://collections.library.yale.edu/catalog/2065791.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 385 | Folder 5806"])(1939 May 28)[March, Fredric]. https://collections.library.yale.edu/catalog/2065791.