1. American Society of Civil Engineers (2009) 2009 Report Card for America’s Infrastructure. ASCE, Reston
2. Arrow K, Dasgupta P, Goulder L, Daily G, Ehrlich P, Heal G, Levin S, Mäler K-G, Schneider S, Starrett D, Walker B (2004) Are we consuming too much? J Econ Perspect 18:147–172
3. Barbasi AL (2002) Linked: the new science of networks. Perseus, Cambridge
4. Biello D (2008) Eco-cities: urban planning for the future. Scientific American, September 24, http://www.scientificamerican.com/article.cfm?id=eco-cities-urban-planning
5. Briscoe S (2005) Numbers in the news: the growth gap within countries. Financ Times 6:16