MLA

Kissinger, Henry, 1923-2023. Hargadon, Thomas. Box 135, folder 1. Circa 1967. https://collections.library.yale.edu/catalog/11784714.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 135, folder 1"])(Circa 1967)[Hargadon, Thomas]. https://collections.library.yale.edu/catalog/11784714.