MLA

Van Thal, Herbert, 1904-1983. Williams, George Charles. Box 2, folder 130. 1936 Feb 25. https://collections.library.yale.edu/catalog/16546034.

APA, 6th edition

Van Thal, Herbert, 1904-1983. (["Box 2, folder 130"])(1936 Feb 25)[Williams, George Charles]. https://collections.library.yale.edu/catalog/16546034.