Music/Hymnis
MLA
Koch, Frederick R. (Frederick Robinson). Music/Hymnis. Box 250, folder 1592. n.d.. https://collections.library.yale.edu/catalog/10172396.
APA, 6th edition
Koch, Frederick R. (Frederick Robinson). (["Box 250, folder 1592"])(n.d.)[Music/Hymnis]. https://collections.library.yale.edu/catalog/10172396.