John C. Bogle (2010). “The Little Book of Common Sense Investing: The Only Way to Guarantee Your Fair Share of Stock Market Returns”, p.48, John Wiley & Sons
"CNBC Exclusive: Liz Claman Interviews Warren Buffett, Berkshire Hathaway Chairman & CEO, Live at the Company's Annual Shareholder's Meeting in Omaha, Nebraska on "Squawk on the Street"". "Squawk On The Street" with Liz Claman, www.cnbc.com. May 7, 2007.