MLA

Kissinger, Henry, 1923-2023. Spofford, Charles. Box 56, folder 8. 1963-1965. https://collections.library.yale.edu/catalog/11783464.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 56, folder 8"])(1963-1965)[Spofford, Charles]. https://collections.library.yale.edu/catalog/11783464.