MLA

Kissinger, Henry, 1923-2023. Fredericks, Wayne. Box 161, folder 13. 1960 May. https://collections.library.yale.edu/catalog/11785202.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 161, folder 13"])(1960 May)[Fredericks, Wayne]. https://collections.library.yale.edu/catalog/11785202.