"The Closing of the American Mind: How higher education has failed democracy and impoverished the souls of today's students". Book by Allan Bloom, 1987.
Thomas Carlyle, Rodger L. Tarr, Mark Engel (2000). “Sartor Resartus: The Life and Opinions of Herr Teufelsdröckh in Three Books”, p.129, Univ of California Press
Letter to "The Keicomolo" - Kleiner, Cole, and Moe (October 1916), in "Selected Letters I, 1911-1924" edited by August Derleth and Donald Wandrei, (p. 27), 1964.