MLA

Kissinger, Henry, 1923-2023. Imperial Defence College. Box 31, folder 5. 1960-1968. https://collections.library.yale.edu/catalog/11782909.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 31, folder 5"])(1960-1968)[Imperial Defence College]. https://collections.library.yale.edu/catalog/11782909.