MLA

Kilpatrick, Jack Frederick (1915-1967). Sermon?. Box 7, folder 536. 1914 August 11. https://collections.library.yale.edu/catalog/15492765.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 7, folder 536"])(1914 August 11)[Sermon?]. https://collections.library.yale.edu/catalog/15492765.