MLA

Van Vechten, Carl, 1880-1964. Perkins, Mildred. Box 100, folder 1802. 1937 November 10. https://collections.library.yale.edu/catalog/2027137.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 100, folder 1802"])(1937 November 10)[Perkins, Mildred]. https://collections.library.yale.edu/catalog/2027137.