MLA

Hughes, Langston, 1902-1967. Barber, Stephanie. Box 12, folder 270. 1954-63, n.d.. https://collections.library.yale.edu/catalog/16998730.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 12, folder 270"])(1954-63, n.d.)[Barber, Stephanie]. https://collections.library.yale.edu/catalog/16998730.