MLA

Kilpatrick, Jack Frederick (1915-1967). Unidentified. Box 6, folder 462. undated. https://collections.library.yale.edu/catalog/15492371.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 6, folder 462"])(undated)[Unidentified]. https://collections.library.yale.edu/catalog/15492371.