MLA

Hughes, Langston, 1902-1967. The American Society of African Culture's [AMSAC] Conference of Negro Writers: drafts of speech, typescript and carbon, corrected. Box 482, folder 12161. 1959, n.d.. https://collections.library.yale.edu/catalog/17034178.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 482, folder 12161"])(1959, n.d.)[The American Society of African Culture's [AMSAC] Conference of Negro Writers: drafts of speech, typescript and carbon, corrected]. https://collections.library.yale.edu/catalog/17034178.