MLA

Koch, Frederick R. (Frederick Robinson). Music/Vélléda. Box 97, folder 1439. 1880-81. https://collections.library.yale.edu/catalog/2067855.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 97, folder 1439"])(1880-81)[Music/Vélléda]. https://collections.library.yale.edu/catalog/2067855.