MLA

Kissinger, Henry, 1923-2023. Buchan, Alastair. Box 300, folder 2. 1968-1969. https://collections.library.yale.edu/catalog/11774491.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 300, folder 2"])(1968-1969)[Buchan, Alastair]. https://collections.library.yale.edu/catalog/11774491.