Ralph Waldo Emerson, Robert Ernest Spiller, Alfred Riggs Ferguson, Joseph Slater, Jean Ferguson Carr (1971). “The Collected Works of Ralph Waldo Emerson: Nature, addresses, and lectures”, p.28, Harvard University Press
Ralph Waldo Emerson (1844). “An Address Delivered in the Court-house in Concord, Massachusetts, on 1st August, 1844: On the Anniversary of the Emancipation of the Negroes in the British West Indies”, p.30