MLA

Kissinger, Henry, 1923-2023. "Problems of American Foreign Policy," Brigham Young University, Mar 26, 1964. Box 252, folder 8. Circa 1964. https://collections.library.yale.edu/catalog/11786583.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 252, folder 8"])(Circa 1964)["Problems of American Foreign Policy," Brigham Young University, Mar 26, 1964]. https://collections.library.yale.edu/catalog/11786583.