Saint Thomas (Aquinas) (2000). “The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church's Greatest Theologian”, p.78, Sophia Institute Press
Mikhail Sergeevich Gorbachev (1990). “A Road to the Future: Address by Mikhail Sergeyevich Gorbachev, General Secretary of the Central Committee of the Communist Party of the Soviet Union ... at the Plenary Meeting of the Forty-third Session of the United Nations General Assembly, in New York, Wednesday, December 7, 1988”