Lawrence A. Cunningham, Warren E. Buffett (2013). “The Essays of Warren Buffett: Lessons for Corporate America (Third Edition)”, p.71, Carolina Academic Press
Lawrence A. Cunningham, Warren E. Buffett (2013). “The Essays of Warren Buffett: Lessons for Corporate America (Third Edition)”, p.71, Carolina Academic Press
"Seizing the Opportunities of Global Urbanization: The New Frontier in America’s International Economic Policy" by Robert Hormats, www.huffingtonpost.com. March 25, 2013.