Albert Einstein (2015). “Bite-Size Einstein: Quotations on Just About Everything from the Greatest Mind of the Twentieth Century”, p.56, St. Martin's Press
Speech in Ottawa on January 10, 1946. "Eisenhower Speaks: Dwight D. Eisenhower in His Messages and Speeches". Book edited by Rudolph L. Treuenfels, 1948.
Mahatma Gandhi (1965). “Glorious Thoughts of Gandhi: Being a Treasury of about Ten Thousand Valuable and Inspiring Thougths of Mahatma Gandhi, Classified Under Four Hundred Subjects”