MLA

Stein, Gertrude, 1874-1946. Van Vechten, Carl. Box 129, folder 2812-2822. 1930-46, n.d.. https://collections.library.yale.edu/catalog/11705691.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 129, folder 2812-2822"])(1930-46, n.d.)[Van Vechten, Carl]. https://collections.library.yale.edu/catalog/11705691.