John Keats (2015). “The Complete Poetry of John Keats: Ode on a Grecian Urn + Ode to a Nightingale + Hyperion + Endymion + The Eve of St. Agnes + Isabella + Ode to Psyche + Lamia + Sonnets and more from one of the most beloved English Romantic poets”, p.546, e-artnow
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.10, Skyhorse Publishing, Inc.