Cite

Trumpet, John. Writing practice

MLA

Kilpatrick, Jack Frederick (1915-1967). Trumpet, John. Writing practice. Box 7, folder 570. undated. https://collections.library.yale.edu/catalog/15492870.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 7, folder 570"])(undated)[Trumpet, John. Writing practice]. https://collections.library.yale.edu/catalog/15492870.