MLA

Hughes, Langston, 1902-1967. Mills, Florence. Box 20, folder 281. 1875-1978. https://collections.library.yale.edu/catalog/16207058.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 20, folder 281"])(1875-1978)[Mills, Florence]. https://collections.library.yale.edu/catalog/16207058.