1. Census regions and divisions of the United States;USCB,2010
2. Monthly Electric Utility Sales and Revenues with State Distributions Report,2016
3. Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel;USEPA,2005
4. The Emissions & Generation Resource Integrated Database (eGRID);USEPA,2015
5. Fast Facts: U.S. Transportation Sector Greenhouse Gas Emissions 1990-2016,2018