MLA

Koch, Frederick R. (Frederick Robinson). Music/Nerone, act II. Box 274, folder 1616. 1933-34. https://collections.library.yale.edu/catalog/31907878.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 274, folder 1616"])(1933-34)[Music/Nerone, act II]. https://collections.library.yale.edu/catalog/31907878.