MLA

Koch, Frederick R. (Frederick Robinson). Other correspondents. Box 52, folder 1111. 1905-31. https://collections.library.yale.edu/catalog/2065840.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 52, folder 1111"])(1905-31)[Other correspondents]. https://collections.library.yale.edu/catalog/2065840.