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”
Robert Green Ingersoll (1898). “Lectures of Col. R.G. Ingersoll: Including His Answers to the Clergy, His Oration at His Brother's Grave, Etc., Etc. : Complete”