MLA

Kissinger, Henry, 1923-2023. Ahlers, Conrad. Box 1, folder 15. 1963-1967. https://collections.library.yale.edu/catalog/11782294.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 1, folder 15"])(1963-1967)[Ahlers, Conrad]. https://collections.library.yale.edu/catalog/11782294.