1. REN21 (Renewable Energy Policy Network for the 21st Century), Renewables 2007: Global Status Report,2007
2. Small geothermal power plants: design, performance and economics;DiPippo;GHC Bulletin,1999
3. Geothermal energy for the benefit of the people;Fridleifsson;Renewable and Sustainable Energy Reviews,2001
4. Geothermal energy technology and current status: an overview;Barbier;Renewable and Sustainable Energy Reviews,2002
5. Characteristics, development and utilization of geothermal resources;Lund;GHC Bulletin,2007