Russell Conwell (2013). “Acres of Diamonds: 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.17, Lulu Press, Inc
Russell Conwell (2013). “Acres of Diamonds: 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.38, Lulu Press, Inc