MLA

Van Vechten, Carl, 1880-1964. Hallaway, Mary Lee. Box 92, folder 1591. 1939 May 16. https://collections.library.yale.edu/catalog/2022876.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 92, folder 1591"])(1939 May 16)[Hallaway, Mary Lee]. https://collections.library.yale.edu/catalog/2022876.