T. Colin Campbell, Thomas M. Campbell (II.) (2006). “The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-term Health”, p.75, BenBella Books
William James (2013). “Pragmatism: The Secret Edition - Open Your Heart to the Real Power and Magic of Living Faith and Let the Heaven Be in You, Go Deep Inside Yourself and Back, Feel the Crazy and Divine Love and Live for Your Dreams”, p.10, Lulu Press, Inc