MLA

Warren, Robert Penn, 1905-1989. Clark, Elias. Box 17, folder 315. 1962-79. https://collections.library.yale.edu/catalog/17096910.

APA, 6th edition

Warren, Robert Penn, 1905-1989. (["Box 17, folder 315"])(1962-79)[Clark, Elias]. https://collections.library.yale.edu/catalog/17096910.