MLA

Hughes, Langston, 1902-1967. League of American Writers. Box 101, folder 1897. 1932-43, n.d.. https://collections.library.yale.edu/catalog/10606947.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 101, folder 1897"])(1932-43, n.d.)[League of American Writers]. https://collections.library.yale.edu/catalog/10606947.