MLA

Hughes, Langston, 1902-1967. Life Extension Institute. Box 103, folder 1949. 1929. https://collections.library.yale.edu/catalog/32586010.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 103, folder 1949"])(1929)[Life Extension Institute]. https://collections.library.yale.edu/catalog/32586010.