1. Armstead, H., & Tester, J. (1987). Heat mining. New Fetter Lane, London: E. & F. N. Spon Ltd.
2. Tester, J., et al. (2006). The future of geothermal energy—impact of enhanced geothermal systems (EGS) on the US in the 21st, Idaho Falls, Idaho.: Idaho National Laboratory.
3. Boldizsar, T. (1970). Geothermal energy production from porous sediments in Hungary. Geothermics, 2.
4. Árpási, M. (2003). Geothermal development in Hungary—country update report 2000–2002. Geothermics, 371–377.
5. Erlingsson, T., Jóhannesson, T., Olafsson, E. & Axelsson, G., (2010). Geothermal District Heating System in XianYang, Shaanxi, China. Proceedings World Geothermal Congress. Bali, Indonesia.