MLA

Hughes, Langston, 1902-1967. Holiday, Billie. Box 80, folder 1534. 1948, n.d.. https://collections.library.yale.edu/catalog/17394766.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 80, folder 1534"])(1948, n.d.)[Holiday, Billie]. https://collections.library.yale.edu/catalog/17394766.