MLA

Van Vechten, Carl, 1880-1964. Waters, Ethel. Box 107, folder 1958. 1934 April 30. https://collections.library.yale.edu/catalog/2028453.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 107, folder 1958"])(1934 April 30)[Waters, Ethel]. https://collections.library.yale.edu/catalog/2028453.