MLA

Kissinger, Henry, 1923-2023. Kline, Charles. Box 35, folder 22. 1958-1959, undated. https://collections.library.yale.edu/catalog/11783009.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 35, folder 22"])(1958-1959, undated)[Kline, Charles]. https://collections.library.yale.edu/catalog/11783009.