MLA

Van Vechten, Carl, 1880-1964. Denman, Phil, with Owen Dodson, Allen Porter, Frank "Killer Joe" Piro, Charles Sebree, and Don Smith. Box 110, folder 2039. 1943 February 17. https://collections.library.yale.edu/catalog/2028030.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 110, folder 2039"])(1943 February 17)[Denman, Phil, with Owen Dodson, Allen Porter, Frank "Killer Joe" Piro, Charles Sebree, and Don Smith]. https://collections.library.yale.edu/catalog/2028030.