MLA

Hughes, Langston, 1902-1967. Anderson, Marian. Box 19, folder 231. 1964. https://collections.library.yale.edu/catalog/16207012.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 19, folder 231"])(1964)[Anderson, Marian]. https://collections.library.yale.edu/catalog/16207012.