MLA

Koch, Frederick R. (Frederick Robinson). Audel, Stéphane. Box 47, folder 966. [1955]. https://collections.library.yale.edu/catalog/16601837.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 47, folder 966"])([1955])[Audel, Stéphane]. https://collections.library.yale.edu/catalog/16601837.