MLA

Hughes, Langston, 1902-1967. Kay, Ulysses. Box 95, folder 1786-1788. 1945-63, n.d.. https://collections.library.yale.edu/catalog/16998784.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 95, folder 1786-1788"])(1945-63, n.d.)[Kay, Ulysses]. https://collections.library.yale.edu/catalog/16998784.