"Think Like a Freak extract: joining the dots between hot dogs, Van Halen and David Cameron" by Steven Levitt and Stephen Dubner, www.theguardian.com. May 10, 2014.
Steven D. Levitt, Stephen J. Dubner (2010). “SuperFreakonomics, Illustrated edition: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance”, p.44, Harper Collins
Steven D. Levitt, Stephen J. Dubner (2010). “SuperFreakonomics, Illustrated edition: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance”, p.31, Harper Collins
Stephen J. Dubner, Steven D. Levitt (2010). “Superfreakonomics: Global Cooling, Patriotic Prostitutes and Why Suicide Bombers Should Buy Life Insurance”, p.77, Penguin UK