MLA

Van Vechten, Carl, 1880-1964. Adamic, Louis. Box 330, folder 4080. 1937 July 27. https://collections.library.yale.edu/catalog/2029390.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 330, folder 4080"])(1937 July 27)[Adamic, Louis]. https://collections.library.yale.edu/catalog/2029390.