MLA

Hughes, Langston, 1902-1967. Ellis, Havelock. Box 59, folder 1118. 1927 Apr 5. https://collections.library.yale.edu/catalog/11019063.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 59, folder 1118"])(1927 Apr 5)[Ellis, Havelock]. https://collections.library.yale.edu/catalog/11019063.