MLA

Coady, R. J. (Robert J.), 1876-1921. Coady, R.J. letters. Box 1 | Folder 2. 1916, 1920, n.d.. https://collections.library.yale.edu/catalog/17364896.

APA, 6th edition

Coady, R. J. (Robert J.), 1876-1921. (["Box 1 | Folder 2"])(1916, 1920, n.d.)[Coady, R.J. letters]. https://collections.library.yale.edu/catalog/17364896.