MLA

Kissinger, Henry, 1923-2023. Frost, David. Box 361, folder 15. 1970-1973. https://collections.library.yale.edu/catalog/11775402.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 361, folder 15"])(1970-1973)[Frost, David]. https://collections.library.yale.edu/catalog/11775402.