Ralph Waldo Emerson, Robert Ernest Spiller, Alfred Riggs Ferguson, Wallace E. Williams, Joseph Slater (1987). “The Collected Works of Ralph Waldo Emerson: Representative men: seven lectures”, p.152, Harvard University Press
Jeremy Taylor, Charles Page Eden, Reginald Heber, Alexander Taylor (1856). “The Whole Works of the Right Rev. Jeremy Taylor ...: The rule and exercises of holy living and dying”, p.165