MLA

Koch, Frederick R. (Frederick Robinson). Eulogy for Georges Bizet. Box 20, folder 375. [1875 Jun]. https://collections.library.yale.edu/catalog/2007265.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 20, folder 375"])([1875 Jun])[Eulogy for Georges Bizet]. https://collections.library.yale.edu/catalog/2007265.