MLA

Thurman, Wallace, 1902-1934. Hughes, Langston. Box 1, folder 3. 1929, 1932, n.d.. https://collections.library.yale.edu/catalog/16732567.

APA, 6th edition

Thurman, Wallace, 1902-1934. (["Box 1, folder 3"])(1929, 1932, n.d.)[Hughes, Langston]. https://collections.library.yale.edu/catalog/16732567.