MLA

Kissinger, Henry, 1923-2023. "'Explaining What You Are After Is the Secret of Diplomacy',"American Heritage, Aug-Sep 1983. Box 698, folder 11. 1983. https://collections.library.yale.edu/catalog/11781350.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 698, folder 11"])(1983)["'Explaining What You Are After Is the Secret of Diplomacy',"American Heritage, Aug-Sep 1983]. https://collections.library.yale.edu/catalog/11781350.