MLA

Kissinger, Henry, 1923-2023. Defense. Box 215, folder 6. Circa 1968. https://collections.library.yale.edu/catalog/11786051.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 215, folder 6"])(Circa 1968)[Defense]. https://collections.library.yale.edu/catalog/11786051.