MLA

Kilpatrick, Jack Frederick (1915-1967). Unidentified. Box 6, folder 461. undated. https://collections.library.yale.edu/catalog/15492370.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 6, folder 461"])(undated)[Unidentified]. https://collections.library.yale.edu/catalog/15492370.