MLA

Hughes, Langston, 1902-1967. Landi, Erberto. Box 469, folder 11569. n.d.. https://collections.library.yale.edu/catalog/10607150.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 469, folder 11569"])(n.d.)[Landi, Erberto]. https://collections.library.yale.edu/catalog/10607150.