1. U.S. Department of Energy, 2008, Energy Consumption by Sector (1949–2008), http://www.eia.doe.gov/emeu/aer/txt/ptb0201a.html
2. U.S. Department of Energy, 2008, Petroleum Products Supplied by Type (1949–2008), http://www.eia.doe.gov/emeu/aer/txt/ptb0511.html
3. U.S. Department of Energy, 2008, Transportation Sector Energy Consumption Estimates (2007), http://www.eia.doe.gov/emeu/states/sep_sum/html/sum_btu_tra.html
4. U.S. Department of Energy, 2009, Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda, http://genomicscience.energy.gov/biofuels/b2bworkshop.shtml