Robert H. Schuller (1993). “Robert H Schuller: The Inspirational Writings : Tough Times Never Last, But Tough People Do/Tough Minded Faith for Tender Hearted People”, Bbs Publishing Corporation
Ambrose Bierce (2011). “Ambrose Bierce: The Devil's Dictionary, Tales, and Memoirs: The Devil's Dictionary, Tales, and Memoirs”, p.565, Library of America
Robert H. Schuller (1993). “Robert H Schuller: The Inspirational Writings : Tough Times Never Last, But Tough People Do/Tough Minded Faith for Tender Hearted People”, Bbs Publishing Corporation