Joseph Lewis, Robert Green Ingersoll (1957). “Ingersoll the Magnificent: To which Has Been Added a Special Arrangement of Some Gems from Ingersoll for Inspiration, Wisdom, and Courage”
Robert Green Ingersoll (1920). “Ingersoll: Fifty Great Selections, Lectures, Tributes, After Dinner Speeches and Essays, Carefully Selected from the Twelve Volume Dresden Edition of Colonel Ingersoll's Complete Works”
Joseph Lewis, Robert Green Ingersoll (1957). “Ingersoll the Magnificent: To which Has Been Added a Special Arrangement of Some Gems from Ingersoll for Inspiration, Wisdom, and Courage”