MLA

Kissinger, Henry, 1923-2023. Friele, Berent. Box 150, folder 2. 1964 January-April. https://collections.library.yale.edu/catalog/11784984.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 150, folder 2"])(1964 January-April)[Friele, Berent]. https://collections.library.yale.edu/catalog/11784984.