MLA

Hughes, Langston, 1902-1967. Mitchison, Naomi. Box 113, folder 2159. 1934, 1938, n.d.. https://collections.library.yale.edu/catalog/17020438.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 113, folder 2159"])(1934, 1938, n.d.)[Mitchison, Naomi]. https://collections.library.yale.edu/catalog/17020438.