1. Development Indicator. World Bank, Retrieved 12/07/2009, [http://datafinder.worldbank.org/about-world-development-indicators?cid=GPD_WDI]
2. A Guide to Combined Heat and Power Systems for Boiler Owners and Operators. 2004, Oak Ridge National Laboratory, Retrieved 12/07.2009, [http://www1.eere.energy.gov/industry/bestpractices/pdfs/guide_chp_boiler.pdf]
3. Neal Elliott R, Spurr Mark: Combined Heat and Power: Capturing Wasted Energy. 1999, American Council for an Energy Efficient Economy
4. Bridges Jessica: The State of The CHP Industry. 2008, United States Clean Heat and Power Association, (Accessed 12/06/2009), [http://www.epa.gov/chp/documents/meeting_52508_bridges.pdf]
5. Electric power annual - existing capacity by producer type. Retrieved 12/7/2009, [http://www.eia.doe.gov/cneaf/electricity/epa/epat2p3.html]