MLA

Baldwin, James, 1924-1987. Moore, Arthur. Box 2, folder 37. 1944. https://collections.library.yale.edu/catalog/17022613.

APA, 6th edition

Baldwin, James, 1924-1987. (["Box 2, folder 37"])(1944)[Moore, Arthur]. https://collections.library.yale.edu/catalog/17022613.