MLA

Hughes, Langston, 1902-1967. Spencer, Anne. Box 149, folder 2766. 1928-65. https://collections.library.yale.edu/catalog/17020468.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 149, folder 2766"])(1928-65)[Spencer, Anne]. https://collections.library.yale.edu/catalog/17020468.