MLA

Kissinger, Henry, 1923-2023. von Schmidt-Pauli, Edgar. Box 61, folder 18. 1968. https://collections.library.yale.edu/catalog/11783573.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 61, folder 18"])(1968)[von Schmidt-Pauli, Edgar]. https://collections.library.yale.edu/catalog/11783573.