MLA

Van Vechten, Carl, 1880-1964. Wright, Ellen Poplar. Box 109, folder 2006. 1945 October 27. https://collections.library.yale.edu/catalog/2028860.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 109, folder 2006"])(1945 October 27)[Wright, Ellen Poplar]. https://collections.library.yale.edu/catalog/2028860.