MLA

Kissinger, Henry, 1923-2023. United States and Eastern Europe. Box 237, folder 2. Circa 1968. https://collections.library.yale.edu/catalog/11786311.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 237, folder 2"])(Circa 1968)[United States and Eastern Europe]. https://collections.library.yale.edu/catalog/11786311.