MLA

Van Vechten, Carl, 1880-1964. Chadourne, Marc. Box 340, folder 4369. 1934 February 27. https://collections.library.yale.edu/catalog/2031824.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 340, folder 4369"])(1934 February 27)[Chadourne, Marc]. https://collections.library.yale.edu/catalog/2031824.