MLA

Van Vechten, Carl, 1880-1964. Laing, Hugh. Box 358 | Folder 4907. 1940 October 19. https://collections.library.yale.edu/catalog/2055780.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 358 | Folder 4907"])(1940 October 19)[Laing, Hugh]. https://collections.library.yale.edu/catalog/2055780.