Jane Bryant Quinn (2009). “Making the Most of Your Money Now: The Classic Bestseller Completely Revised for the New Economy”, p.691, Simon and Schuster
"Berkshire’s Corporate Performance vs. the S&P 500". "2007 Chairman’s letter" by Warren Buffett, Fanciful Figures – How Public Companies Juice Earnings, p.18, www.berkshirehathaway.com. February, 2008.