MLA

Kissinger, Henry, 1923-2023. "A Problem in U.S. Foreign Policy: The USSR," Principia College Public Affairs Conference, Apr 12, 1956. Box 240, folder 12. 1956 April. https://collections.library.yale.edu/catalog/11786346.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 240, folder 12"])(1956 April)["A Problem in U.S. Foreign Policy: The USSR," Principia College Public Affairs Conference, Apr 12, 1956]. https://collections.library.yale.edu/catalog/11786346.