MLA

Van Thal, Herbert, 1904-1983. King, Robin. Box 1, folder 68. 1960, n.d.. https://collections.library.yale.edu/catalog/16545972.

APA, 6th edition

Van Thal, Herbert, 1904-1983. (["Box 1, folder 68"])(1960, n.d.)[King, Robin]. https://collections.library.yale.edu/catalog/16545972.