MLA

Toomer, Jean, 1894-1967. Dupee, Yvonne. Box 2, folder 66-75. 1927-38, n.d.. https://collections.library.yale.edu/catalog/16725478.

APA, 6th edition

Toomer, Jean, 1894-1967. (["Box 2, folder 66-75"])(1927-38, n.d.)[Dupee, Yvonne]. https://collections.library.yale.edu/catalog/16725478.