MLA

Cohen, Arthur A. (Arthur Allen), 1928-1986. Todd, Ruthven, correspondence. Box 4. 1959-1982. https://collections.library.yale.edu/catalog/17230061.

APA, 6th edition

Cohen, Arthur A. (Arthur Allen), 1928-1986. (["Box 4"])(1959-1982)[Todd, Ruthven, correspondence]. https://collections.library.yale.edu/catalog/17230061.