MLA

Hughes, Langston, 1902-1967. Preliminary sketches and notes. Box 336, folder 5482. n.d.. https://collections.library.yale.edu/catalog/17034057.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 336, folder 5482"])(n.d.)[Preliminary sketches and notes]. https://collections.library.yale.edu/catalog/17034057.