MLA

Benét, Stephen Vincent, 1898-1943. Brandt & Brandt. Box 4, folder 145-152. 1921-1962, undated. https://collections.library.yale.edu/catalog/2067477.

APA, 6th edition

Benét, Stephen Vincent, 1898-1943. (["Box 4, folder 145-152"])(1921-1962, undated)[Brandt & Brandt]. https://collections.library.yale.edu/catalog/2067477.