MLA

Hughes, Langston, 1902-1967. Armstrong, Harry. Box 8, folder 180. 1935-36, n.d.. https://collections.library.yale.edu/catalog/33219418.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 8, folder 180"])(1935-36, n.d.)[Armstrong, Harry]. https://collections.library.yale.edu/catalog/33219418.