MLA

Hughes, Langston, 1902-1967. Weill, Kurt. Box 168, folder 3081. 1946-50, n.d.. https://collections.library.yale.edu/catalog/10103460.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 168, folder 3081"])(1946-50, n.d.)[Weill, Kurt]. https://collections.library.yale.edu/catalog/10103460.