MLA

Kissinger, Henry, 1923-2023. von Guttenberg, Karl. Box 61, folder 14. 1959-1963. https://collections.library.yale.edu/catalog/11783569.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 61, folder 14"])(1959-1963)[von Guttenberg, Karl]. https://collections.library.yale.edu/catalog/11783569.