MLA

Van Vechten, Carl, 1880-1964. Hellström, Louise Shoemaker. Box 353, folder 4747. 1933 May 2. https://collections.library.yale.edu/catalog/2046989.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 353, folder 4747"])(1933 May 2)[Hellström, Louise Shoemaker]. https://collections.library.yale.edu/catalog/2046989.