MLA

Kissinger, Henry, 1923-2023. "Observations on U.S.-Soviet Relations," Heritage Lectures, Heritage Foundation, Jan 14, 1988. Box 709, folder 1. 1988. https://collections.library.yale.edu/catalog/11781574.

APA, 6th edition

Kissinger, Henry, 1923-2023. (["Box 709, folder 1"])(1988)["Observations on U.S.-Soviet Relations," Heritage Lectures, Heritage Foundation, Jan 14, 1988]. https://collections.library.yale.edu/catalog/11781574.