MLA

Van Vechten, Carl, 1880-1964. Pearson, Beatrice. Box 370 | Folder 5261. 1946 December 13. https://collections.library.yale.edu/catalog/10000603.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 370 | Folder 5261"])(1946 December 13)[Pearson, Beatrice]. https://collections.library.yale.edu/catalog/10000603.