MLA

Kissinger, Henry, 1923-2023. Bronk, Detler. Box 198, folder 15. 1968 March. https://collections.library.yale.edu/catalog/11785817.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 198, folder 15"])(1968 March)[Bronk, Detler]. https://collections.library.yale.edu/catalog/11785817.