MLA

Kissinger, Henry, 1923-2023. Former United States secretaries of state. Box 227, folder 33. Undated, circa 1967-circa 2009. https://collections.library.yale.edu/catalog/12480332.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 227, folder 33"])(Undated, circa 1967-circa 2009)[Former United States secretaries of state]. https://collections.library.yale.edu/catalog/12480332.