MLA

Van Vechten, Carl, 1880-1964. Godowsky, Dagmar. Box 350, folder 4666. 1937 February 24. https://collections.library.yale.edu/catalog/2035453.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 350, folder 4666"])(1937 February 24)[Godowsky, Dagmar]. https://collections.library.yale.edu/catalog/2035453.