MLA

Van Vechten, Carl, 1880-1964. Houston, Elsie. Box 93, folder 1629. 1940 November 4. https://collections.library.yale.edu/catalog/2026055.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 93, folder 1629"])(1940 November 4)[Houston, Elsie]. https://collections.library.yale.edu/catalog/2026055.