MLA

Hughes, Langston, 1902-1967. Joseph, Louis. Box 20, folder 268. 1875-1978. https://collections.library.yale.edu/catalog/16207049.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 20, folder 268"])(1875-1978)[Joseph, Louis]. https://collections.library.yale.edu/catalog/16207049.