MLA

Van Vechten, Carl, 1880-1964. Thomson, Virgil. Box 442, folder 7147. 1947 June 4. https://collections.library.yale.edu/catalog/33270826.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 442, folder 7147"])(1947 June 4)[Thomson, Virgil]. https://collections.library.yale.edu/catalog/33270826.