The Best of Robert Ingersoll
What's God Got to Do with It?: Robert Ingersoll on Free Thought, Honest Talk and the Separation of Church and State
Why I Am An Agnostic
The Great Agnostic: Robert Ingersoll and American Freethought
Freethinkers: A History of American Secularism
Caught in the Pulpit: Leaving Belief Behind
Challenging the Bible: Selections from the Writings and Speeches of Robert G. Ingersoll