MLA

Hughes, Langston, 1902-1967. Douglass, Frederick. Box 4 (Oversize), folder 43. 1893-1954. https://collections.library.yale.edu/catalog/16196976.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 4 (Oversize), folder 43"])(1893-1954)[Douglass, Frederick]. https://collections.library.yale.edu/catalog/16196976.