MLA

Hughes, Langston, 1902-1967. American Dialog. Box 6, folder 122. 1966. https://collections.library.yale.edu/catalog/32579340.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 6, folder 122"])(1966)[American Dialog]. https://collections.library.yale.edu/catalog/32579340.