MLA

Kissinger, Henry, 1923-2023. Neustadt, Richard. Box 45, folder 4. 1964-1968. https://collections.library.yale.edu/catalog/11783213.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 45, folder 4"])(1964-1968)[Neustadt, Richard]. https://collections.library.yale.edu/catalog/11783213.