MLA

Hughes, Langston, 1902-1967. Patterson, Raymond. Box 127, folder 2378. 1957-66, n.d.. https://collections.library.yale.edu/catalog/17020445.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 127, folder 2378"])(1957-66, n.d.)[Patterson, Raymond]. https://collections.library.yale.edu/catalog/17020445.