MLA

Kissinger, Henry, 1923-2023. Shaplen, Robert. Box 303, folder 4. 1969. https://collections.library.yale.edu/catalog/11774536.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 303, folder 4"])(1969)[Shaplen, Robert]. https://collections.library.yale.edu/catalog/11774536.