MLA

Hughes, Langston, 1902-1967. Abdul, Raoul. Box 2, folder 14-15. 1955-67, n.d.. https://collections.library.yale.edu/catalog/32603878.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 2, folder 14-15"])(1955-67, n.d.)[Abdul, Raoul]. https://collections.library.yale.edu/catalog/32603878.