Energy Information Administration
Internal Revenue Service (IRS)
IRS Office of Chief Counsel Telephone Directory (as of April 1, 2011)
National Renewable Energy Laboratory (NREL)
U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE)
U.S. Department of Energy (DOE)
U.S. Environmental Protection Agency (EPA)
Federal Energy Regulatory Commission (FERC)
U.S.D.A. Energy Matrix