MLA

Kissinger, Henry, 1923-2023. Du. Box 309, folder 9. 1968-1975. https://collections.library.yale.edu/catalog/11774627.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 309, folder 9"])(1968-1975)[Du]. https://collections.library.yale.edu/catalog/11774627.