Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.31, Skyhorse Publishing, Inc.
Address at the Sorbonne, Paris, 23 Apr. 1910. Richard M. Nixon quoted this passage in his address to the nation announcing his decision to resign the presidency, 8 Aug. 1974. See Theodore Roosevelt 1; Theodore Roosevelt 2; Theodore Roosevelt 5
Socrates, Plato, Aristotle (1967). “Wit and Wisdom of Socrates, Plato, Aristotle: Being a Treasury of Thousands of Glorious, Inspiring and Imperishable Thoughts, Views and Observations of the Three Great Greek Philosophers, Classified Under about Four Hundred Subjects for Comparative Study”
"Wim Wenders talks with WSWS: 'The culture of independent film criticism has gone down the drain'". Interview with Richard Phillips, www.wsws.org. January 10, 2000.