1. British Petroleum, Statistical review of world energy 2009. Available from: http://www.bp.com/productlanding.do?categoryId=6929&contentId=7044622 [accessed 8/21/2009].
2. U.S.D.O.E. http://www.energy.gov/ [accessed 8/21/2009].
3. U.S.D.O.E. Energy information administration. Available from: http://www.eia.doe.gov/ [accessed 8/21/2009].
4. U.S.D.O.E. Office of Management, Budget, and Evaluation (MBE), Office of Budget. Available from: http://www.cfo.doe.gov/crorg/cf30.htm [accessed 8/21/2009].
5. U.S.D.O.E. Energy Efficiency and Renewable Energy. Available from: http://www.eere.energy.gov [accessed 8/21/2009].