Per
MLA
Kissinger, Henry, 1923-2023. Per. Box 444, folder 9. 1981. https://collections.library.yale.edu/catalog/11777896.
APA, 6th edition
Kissinger, Henry, 1923-2023. (["Box 444, folder 9"])(1981)[Per]. https://collections.library.yale.edu/catalog/11777896.