1. Wikipedia (2012). Overpopulation. http://en.wikipedia.org/wiki/Overpopulation . Accessed 1 Dec 2012.
2. Aristotle, (1926). Nicomachean ethics. Loeb Classical Library (Vol. XIX). Cambridge, MA: Harvard University Press.
3. Aristotle, (1932). Politics, Loeb Classical Library (Vol. XXI). Cambridge, MA: Harvard University Press.
4. Arrow, K., et al. (1995). Economic growth, carrying capacity and the environment. Ecological Economics, 15, 91–95.
5. Cohen, J. (1995). How many people can the earth support?. NY: W.W. Norton.