MLA

Hughes, Langston, 1902-1967. Student Letters: M-NYJ. Box 219, folder 3671. 1943-67, n.d.. https://collections.library.yale.edu/catalog/2043792.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 219, folder 3671"])(1943-67, n.d.)[Student Letters: M-NYJ]. https://collections.library.yale.edu/catalog/2043792.