1. Stories from a heated Earth, our geothermal heritage;Cataldi,1999
2. NREL. 2008 Geothermal technologies market report. Washington, DC, US: National Renewable Energy Laboratory (NREL); 2009.
3. Geothermal energy technology and current status: an overview;Barbier;Renew Sustain Energy Rev,2002
4. Geothermal: 2012 international market overview report;Jennejohn,2012
5. Promoting geothermal energy: air emissions comparison and externality analysis;Matek,2013