MLA

Warren, Robert Penn, 1905-1989. Harcourt & Brace. Box 91, folder 1719-27. 1932-63. https://collections.library.yale.edu/catalog/2007682.

APA, 6th edition

Warren, Robert Penn, 1905-1989. (["Box 91, folder 1719-27"])(1932-63)[Harcourt & Brace]. https://collections.library.yale.edu/catalog/2007682.