MLA

Koch, Frederick R. (Frederick Robinson). Godebski, Jean. Box 51, folder 1096. 1913 Apr 12. https://collections.library.yale.edu/catalog/2065833.

APA, 6th edition

Koch, Frederick R. (Frederick Robinson). (["Box 51, folder 1096"])(1913 Apr 12)[Godebski, Jean]. https://collections.library.yale.edu/catalog/2065833.