1. EIA (United States Energy Information Administration), Annual Energy Review 2011; 2012. (accessed 06.02.13).
2. IEA (International Energy Agency. Key World Energy Statistics 2012; 2012. (accessed 06.02.13).
3. IPCC (Intergovernmental Panel on Climate Change). Climate change 2007: The physical science basis. Contribution of working group I to the fourth assessment report; 2007, (accessed 06.02.13).
4. IPCC (Intergovernmental Panel on Climate Change). Guidelines for national greenhouse gas inventories; 2006, (accessed 06.02.2013).
5. NETL (National Energy Technology Laboratory). Life cycle analysis: Integrated Gasification Combined Cycle (IGCC) power plant. Report number DOE/NETL-403-110209; 2010.