MLA

Van Vechten, Carl, 1880-1964. Cusick, Michael Frankau, at the home of Aline Bernstein, Armonk, New York. Box 342, folder 4437. 1947 August 31. https://collections.library.yale.edu/catalog/2032353.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 342, folder 4437"])(1947 August 31)[Cusick, Michael Frankau, at the home of Aline Bernstein, Armonk, New York]. https://collections.library.yale.edu/catalog/2032353.