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An investigation of the technical and economical feasibility of using low temperature geothermal sources in Colorado
Nannen, L. W., (1976)
Heat flow and geothermal studies in the Great Plains
Gosnold, William D., (1985)
Statistics on the production and use of lowtemperature themal water in Ungary
Molnár, Antal, (1984)
Geothermal energy : resources, production, stimulation
Kruger, Paul, (1973)