Cite

Music/Elegie, violin, piano, op. 143, D major

MLA

Koch, Frederick R. (Frederick Robinson). Music/Elegie, violin, piano, op. 143, D major. Box 334, folder 1911. 1915 Jul. https://collections.library.yale.edu/catalog/9999051.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 334, folder 1911"])(1915 Jul)[Music/Elegie, violin, piano, op. 143, D major]. https://collections.library.yale.edu/catalog/9999051.