MLA

Koch, Frederick R. (Frederick Robinson). Music/Jeux. Box 95, folder 1437. [1912]. https://collections.library.yale.edu/catalog/2006105.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 95, folder 1437"])([1912])[Music/Jeux]. https://collections.library.yale.edu/catalog/2006105.