MLA

Van Vechten, Carl, 1880-1964. De Lavallade, Carmen. Box 147, folder 2769. 1955 March 3. https://collections.library.yale.edu/catalog/33289608.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 147, folder 2769"])(1955 March 3)[De Lavallade, Carmen]. https://collections.library.yale.edu/catalog/33289608.