MLA

Koch, Frederick R. (Frederick Robinson). Brewer, Joseph. Box 59, folder 1365. [ca. 1925 May]. https://collections.library.yale.edu/catalog/10079854.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 59, folder 1365"])([ca. 1925 May])[Brewer, Joseph]. https://collections.library.yale.edu/catalog/10079854.