Running Quotes - Page 46
Kenneth Oppel (2005). “Skybreaker”, HarperCollins
John Wesley Powell (2003). “The Exploration of the Colorado River and Its Canyons”, p.268, Penguin
Eric Hoffer (2011). “The True Believer: Thoughts on the Nature of Mass Movements”, p.14, Harper Collins
"Ultramarathon Man". Book by Dean Karnazes, March 17, 2005.