MLA

Kissinger, Henry, 1923-2023. Schlesinger, Arthur, Jr.. Box 54, folder 9. 1962. https://collections.library.yale.edu/catalog/11783415.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 54, folder 9"])(1962)[Schlesinger, Arthur, Jr.]. https://collections.library.yale.edu/catalog/11783415.