MLA

Kissinger, Henry, 1923-2023. Bonn, Germany. Box 771, folder 1. 1975 May 20-21. https://collections.library.yale.edu/catalog/11776587.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 771, folder 1"])(1975 May 20-21)[Bonn, Germany]. https://collections.library.yale.edu/catalog/11776587.