MLA

Kissinger, Henry, 1923-2023. Day. Box 91, folder 5. 2004. https://collections.library.yale.edu/catalog/12479494.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 91, folder 5"])(2004)[Day]. https://collections.library.yale.edu/catalog/12479494.