Mark Twain (1869). “The Innocents Abroad, Or, The New Pilgrims' Progress: Being Some Account of the Steamship Quaker City's Pleasure Excursion to Europe and the Holy Land : with Descriptions of Countries, Nations, Incidents, and Adventures as They Appeared to the Author”, p.546
Mark Twain, Charles Neider (1987). “The outrageous Mark Twain: some lesser-known but extraordinary works : with "Reflections on religion" now in book form for the first time”, Doubleday Books