MLA

Warren, Robert Penn, 1905-1989. Connellan, Leo. Box 18, folder 358. 1975-78. https://collections.library.yale.edu/catalog/17096912.

APA, 6th edition

Warren, Robert Penn, 1905-1989. (["Box 18, folder 358"])(1975-78)[Connellan, Leo]. https://collections.library.yale.edu/catalog/17096912.