MLA

Koch, Frederick R. (Frederick Robinson). Music/Miroirs brûlants. Box 331, folder 1869. 1938. https://collections.library.yale.edu/catalog/16834257.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 331, folder 1869"])(1938)[Music/Miroirs brûlants]. https://collections.library.yale.edu/catalog/16834257.