"Smarter Branding Without Breaking the Bank: Five Proven Marketing Strategies You Can Use Right Now to Build Your Business at Little Or No Cost". Book by Brenda Bence (p. 91), November 7, 2011.
Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.13, Skyhorse Publishing, Inc.