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”
Thomas Jefferson, Henry Augustine Washington (1858). “The life and letters of Thomas Jefferson: being his autobiography and select correspondence, from original manuscripts”, p.187
Ludwig van Beethoven, Friedrich Kerst, Henry Edward Krehbiel (1964). “Beethoven, the Man and the Artist, as Revealed in His Own Words”, p.106, Courier Corporation