Bill Welter, Jean Egmon (2005). “The Prepared Mind of a Leader: Eight Skills Leaders Use to Innovate, Make Decisions, and Solve Problems”, p.45, John Wiley & Sons
Colin Beavan (2009). “No Impact Man: The Adventures of a Guilty Liberal Who Attempts to Save the Planet, and the Discoveries He Makes About Himself and Our Way of Life in the Process”, p.45, Farrar, Straus and Giroux