MLA

Hughes, Langston, 1902-1967. Arden, Elsie. Box 8, folder 173. 1935-41, n.d.. https://collections.library.yale.edu/catalog/33219321.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 8, folder 173"])(1935-41, n.d.)[Arden, Elsie]. https://collections.library.yale.edu/catalog/33219321.