MLA

Kissinger, Henry, 1923-2023. China. Box 228, folder 18. 1973 February. https://collections.library.yale.edu/catalog/12480781.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 228, folder 18"])(1973 February)[China]. https://collections.library.yale.edu/catalog/12480781.