MLA

Hughes, Langston, 1902-1967. Marshall, Thurgood. Box 469, folder 11591. 1958, n.d.. https://collections.library.yale.edu/catalog/2052754.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 469, folder 11591"])(1958, n.d.)[Marshall, Thurgood]. https://collections.library.yale.edu/catalog/2052754.