Yvon Chouinard (2016). “Let My People Go Surfing: The Education of a Reluctant Businessman--Including 10 More Years of Business Unusual”, p.211, Penguin
Prentice Mulford (2015). “Thoughts Are Things & The God In You - Connect With The Force Within Yourself: How to Find With Your Inner Power - From one of the New Thought pioneers, author of Your Forces and How to Use Them, Gift of Spirit & The Gift of Understanding”, p.120, e-artnow