MLA

Koch, Frederick R. (Frederick Robinson). Music/Un grand sommeil noire. Box 332, folder 1884. 1895 Aug 6. https://collections.library.yale.edu/catalog/15947415.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 332, folder 1884"])(1895 Aug 6)[Music/Un grand sommeil noire]. https://collections.library.yale.edu/catalog/15947415.