MLA

Kissinger, Henry, 1923-2023. Messages received, Q. Box 150, folder 2. 1969. https://collections.library.yale.edu/catalog/12479736.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 150, folder 2"])(1969)[Messages received, Q]. https://collections.library.yale.edu/catalog/12479736.