MLA

Van Vechten, Carl, 1880-1964. Porter, Allen. Box 664, folder 14659. 1933 October 20. https://collections.library.yale.edu/catalog/33270858.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 664, folder 14659"])(1933 October 20)[Porter, Allen]. https://collections.library.yale.edu/catalog/33270858.