Jack Canfield, Kent Healy (2010). “The Success Principles for Teens: How to Get From Where You Are to Where You Want to Be”, p.29, Health Communications, Inc.
Jack Canfield, Mark Victor Hansen (2012). “Chicken Soup for the Soul in the Classroom Middle School Edition: Grades 6–8: Lesson Plans and Students' Favorite Stories for Reading Comprehension, Writing Skills, Critical Thinking, Character Building”, p.433, Simon and Schuster