MLA

Koch, Frederick R. (Frederick Robinson). Unidentified. Box 52, folder 1112. 1916, [1922?]. https://collections.library.yale.edu/catalog/2065841.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 52, folder 1112"])(1916, [1922?])[Unidentified]. https://collections.library.yale.edu/catalog/2065841.