MLA

Van Vechten, Carl, 1880-1964. Frohman, Daniel. Box 349 | Folder 4627. 1934 October 15. https://collections.library.yale.edu/catalog/2034812.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 349 | Folder 4627"])(1934 October 15)[Frohman, Daniel]. https://collections.library.yale.edu/catalog/2034812.