MLA

Kissinger, Henry, 1923-2023. Erwin, Robert. Box 121, folder 8. 1964-1967. https://collections.library.yale.edu/catalog/11784466.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 121, folder 8"])(1964-1967)[Erwin, Robert]. https://collections.library.yale.edu/catalog/11784466.