MLA

Kissinger, Henry, 1923-2023. Y. Box 546, folder 4. 1999. https://collections.library.yale.edu/catalog/11779343.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 546, folder 4"])(1999)[Y]. https://collections.library.yale.edu/catalog/11779343.