MLA

Wallerstein, Immanuel Maurice, 1930-. Freedom Concert. Box 2. undated. https://collections.library.yale.edu/catalog/32205561.

APA, 6th edition

Wallerstein, Immanuel Maurice, 1930-. (["Box 2"])(undated)[Freedom Concert]. https://collections.library.yale.edu/catalog/32205561.