MLA

Hughes, Langston, 1902-1967. Three Poems, draft, typescript, carbon. Box 424, folder 9420. n.d.. https://collections.library.yale.edu/catalog/17394783.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 424, folder 9420"])(n.d.)[Three Poems, draft, typescript, carbon]. https://collections.library.yale.edu/catalog/17394783.