MLA

Kissinger, Henry, 1923-2023. Correspondence. Box 274, folder 4. 1957 January-May. https://collections.library.yale.edu/catalog/11786903.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 274, folder 4"])(1957 January-May)[Correspondence]. https://collections.library.yale.edu/catalog/11786903.