1. Autobahn History 2010 http://www.german-autobahn.eu/index.asp?page=history
2. Blair , E. S. Svitana , K. Manduca , C. Leather Tanning in Woburn 2009 http://serc.carleton.edu/woburn/issues/tanning.html
3. “Embedded in Nature: Human Health and Biodiversity,”;Chivian;Environmental Health Perspectives,2004
4. “Fueling Population Growthin Las Vegas: How Large-Scale Groundwater Withdrawal Could Burn Regional Biodiversity,”;Deacon;Bioscience,2007