Mark Twain (2017). “Mark Twain, the Globetrotter: Complete Travel Books, Memoirs & Anecdotes (Illustrated Edition): A Tramp Abroad, The Innocents Abroad, Roughing It, Old Times on the Mississippi, Life on the Mississippi, Following the Equator & Some Rambling Notes of an Idle Excursion, With Author’s Biography”, p.1235, e-artnow
"Doyen of American critics turns his back on the 'nasty, stupid' world of modern art" by Edward Helmore, Paul Gallagher, www.theguardian.com. October 27, 2012.