MLA

Kilpatrick, Jack Frederick (1915-1967). Unidentified. Box 7, folder 540. 1926. https://collections.library.yale.edu/catalog/15492769.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 7, folder 540"])(1926)[Unidentified]. https://collections.library.yale.edu/catalog/15492769.