MLA

Koch, Frederick R. (Frederick Robinson). Notes and ephemera. Box 50, folder 1070. 1893-[20], n.d.. https://collections.library.yale.edu/catalog/16228733.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 50, folder 1070"])(1893-[20], n.d.)[Notes and ephemera]. https://collections.library.yale.edu/catalog/16228733.