MLA

Van Vechten, Carl, 1880-1964. Andrews, Ann. Box 332, folder 4129. 1938 June 2. https://collections.library.yale.edu/catalog/2029409.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 332, folder 4129"])(1938 June 2)[Andrews, Ann]. https://collections.library.yale.edu/catalog/2029409.