MLA

Kissinger, Henry, 1923-2023. Hoepli, Nancy. Box 161, folder 21. 1960. https://collections.library.yale.edu/catalog/11785210.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 161, folder 21"])(1960)[Hoepli, Nancy]. https://collections.library.yale.edu/catalog/11785210.