Cite

Music/Quartet, strings, no. 2, A minor

MLA

Koch, Frederick R. (Frederick Robinson). Music/Quartet, strings, no. 2, A minor. Box 301, folder 1643. [1947]. https://collections.library.yale.edu/catalog/2067765.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 301, folder 1643"])([1947])[Music/Quartet, strings, no. 2, A minor]. https://collections.library.yale.edu/catalog/2067765.