MLA

Warren, Robert Penn, 1905-1989. Malcolm X. Box 209, folder 3658. 1964. https://collections.library.yale.edu/catalog/2014979.

APA, 6th edition

Warren, Robert Penn, 1905-1989. (["Box 209, folder 3658"])(1964)[Malcolm X]. https://collections.library.yale.edu/catalog/2014979.