MLA

Kissinger, Henry, 1923-2023. Hannigan, Mary. Box 27, folder 17. 1967. https://collections.library.yale.edu/catalog/11782820.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 27, folder 17"])(1967)[Hannigan, Mary]. https://collections.library.yale.edu/catalog/11782820.