MLA

Van Vechten, Carl, 1880-1964. Perkins, Loretta. Box 100 | Folder 1799. 1941 April 7. https://collections.library.yale.edu/catalog/2027073.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 100 | Folder 1799"])(1941 April 7)[Perkins, Loretta]. https://collections.library.yale.edu/catalog/2027073.