MLA

Van Vechten, Carl, 1880-1964. Lerman, Leo. Box 361, folder 4985. 1948 May 2. https://collections.library.yale.edu/catalog/2056413.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 361, folder 4985"])(1948 May 2)[Lerman, Leo]. https://collections.library.yale.edu/catalog/2056413.