Napoleon Hill (1960). “The Law of Success in Sixteen Lessons: Teaching, for the First Time in the History of the World, the True Philosophy Upon which All Personal Success is Built”
John Ortberg, Stephen Sorenson, Amanda Sorenson (2003). “If You Want to Walk on Water, You've Got to Get Out of the Boat: A 6-session Journey on Learning to Trust God”, p.195, Zondervan
Wallace D. Wattles (2015). “Wallace D. Wattles Ultimate Collection – 10 Books in One Volume: The Science of Getting Rich, The Science of Being Well, The Science of Being Great, How to Get What You Want and more: From one of the New Thought pioneers, author of Making of the Man Who Can or How to Promote Yourself and New Science of Living and Healing or Health Through New Thought and Fasting”, p.69, e-artnow