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.69, Harvard University Press
Ralph Waldo Emerson (2004). “A Dream Too Wild: Emerson Meditations for Every Day of the Year”, p.20, Unitarian Universalist Association of Congregations