James Boswell, Samuel Johnson (1824). “The Life of Samuel Johnson, LL. D., Comprehending an Account of His Studies, and Numerous Works, in Chronological Order: A Series of His Epistolary Correspondence and Conversations with Many Eminent Persons; and Various Original Pieces of His Composition, Never Before Published; the Whole Exhibiting a View of Literature and Literary Men in Great Britain, for Near Half a Century During which He Flourished”, p.6
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.17, Skyhorse Publishing, Inc.
George Bernard Shaw (2015). “George Bernard Shaw: Collected Articles, Lectures, Essays and Letters: Thoughts and Studies from the Renowned Dramaturge and Author of Mrs. Warren’s Profession, Pygmalion, Arms and The Man, Saint Joan, Caesar and Cleopatra, Androcles And The Lion”, p.309, e-artnow