MLA

Van Vechten, Carl, 1880-1964. Davison, Robert. Box 343, folder 4455. 1948 March 30. https://collections.library.yale.edu/catalog/2032465.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 343, folder 4455"])(1948 March 30)[Davison, Robert]. https://collections.library.yale.edu/catalog/2032465.