MLA

Hughes, Langston, 1902-1967. American Negro Theatre. Box 6, folder 134. 1946. https://collections.library.yale.edu/catalog/32579583.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 6, folder 134"])(1946)[American Negro Theatre]. https://collections.library.yale.edu/catalog/32579583.