MLA

Van Vechten, Carl, 1880-1964. Thurman, Wallace. Box 46, folder 852. 1927 [March?]. https://collections.library.yale.edu/catalog/10267791.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 46, folder 852"])(1927 [March?])[Thurman, Wallace]. https://collections.library.yale.edu/catalog/10267791.