MLA

Kissinger, Henry, 1923-2023. Unidentified. Box 339, folder 7. 1974-1976, undated. https://collections.library.yale.edu/catalog/11775063.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 339, folder 7"])(1974-1976, undated)[Unidentified]. https://collections.library.yale.edu/catalog/11775063.