MLA

Kissinger, Henry, 1923-2023. Z. Box 35, folder 2. 2006. https://collections.library.yale.edu/catalog/12482156.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 35, folder 2"])(2006)[Z]. https://collections.library.yale.edu/catalog/12482156.