MLA

Hughes, Langston, 1902-1967. Mexico. Box 458, folder 11066-11066a. ca. 1919-20. https://collections.library.yale.edu/catalog/10590987.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 458, folder 11066-11066a"])(ca. 1919-20)[Mexico]. https://collections.library.yale.edu/catalog/10590987.