MLA

Kissinger, Henry, 1923-2023. Feldstein, Martin. Box 605, folder 12. 1997. https://collections.library.yale.edu/catalog/11780156.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 605, folder 12"])(1997)[Feldstein, Martin]. https://collections.library.yale.edu/catalog/11780156.