MLA

Matthiessen, F. O. (Francis Otto), 1902-1950. Lamont, Corliss. Box 3. 1942 November 23. https://collections.library.yale.edu/catalog/32239729.

APA, 6th edition

Matthiessen, F. O. (Francis Otto), 1902-1950. (["Box 3"])(1942 November 23)[Lamont, Corliss]. https://collections.library.yale.edu/catalog/32239729.