MLA

Benét, William Rose, 1886-1950. Stevens, Wallace. Box 103, folder 3178. [circa 1936]. https://collections.library.yale.edu/catalog/10268767.

APA, 6th edition

Benét, William Rose, 1886-1950. (["Box 103, folder 3178"])([circa 1936])[Stevens, Wallace]. https://collections.library.yale.edu/catalog/10268767.