MLA

Kissinger, Henry, 1923-2023. Lowenthal, David. Box 39, folder 6. 1961-1963. https://collections.library.yale.edu/catalog/11783088.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 39, folder 6"])(1961-1963)[Lowenthal, David]. https://collections.library.yale.edu/catalog/11783088.