MLA

Kissinger, Henry, 1923-2023. Speakers-Hilsman, Roger. Box 130, folder 19. 1968 March 25. https://collections.library.yale.edu/catalog/11784630.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 130, folder 19"])(1968 March 25)[Speakers-Hilsman, Roger]. https://collections.library.yale.edu/catalog/11784630.