MLA

Kissinger, Henry, 1923-2023. N. Box 298, folder 1. 1969-1975, undated. https://collections.library.yale.edu/catalog/11774450.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 298, folder 1"])(1969-1975, undated)[N]. https://collections.library.yale.edu/catalog/11774450.