MLA

Koch, Frederick R. (Frederick Robinson). Music/Les contes d'Hoffmann. Box 166, folder 1508. 1880, n.d.. https://collections.library.yale.edu/catalog/2004879.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 166, folder 1508"])(1880, n.d.)[Music/Les contes d'Hoffmann]. https://collections.library.yale.edu/catalog/2004879.