MLA

Van Vechten, Carl, 1880-1964. Smallens, Alexander. Box 376, folder 5442. 1934 February 23. https://collections.library.yale.edu/catalog/10054123.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 376, folder 5442"])(1934 February 23)[Smallens, Alexander]. https://collections.library.yale.edu/catalog/10054123.