MLA

Koch, Frederick R. (Frederick Robinson). Music/Fantasie, piano, 4 hands, D. 940, F minor. Box 334, folder 1915. 1828 Jan. https://collections.library.yale.edu/catalog/2054740.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 334, folder 1915"])(1828 Jan)[Music/Fantasie, piano, 4 hands, D. 940, F minor]. https://collections.library.yale.edu/catalog/2054740.