1. Koji Morita, Masashi Ogawa, Geothermal and solar heat used to melt snow on roads. Technical Brochure, CADDET Centre for Renewable Energy, IEA, Organization for Economic Co-operation and Development (OECD), Harwell, United Kingdom, 1998.
2. Walter J. Eugster, Jürg Schatzmann, Harnessing solar energy for winter road clearing on heavily loaded expressways, in: Proceeding of XIth PIARC International Winter Road Congress, January 2002, Sapporo, Japan.
3. D. Derwin, P. Booth, P. Zaleski, W. Marsey, W. Flood Jr., SNOWFREE®-Heated Pavement System to Eliminate Icy Runways, SAE Technical Paper Series 2003-01-2145, 2003.
4. Geir Eggen, Geir Vangsnes, Heat pump for district cooling and heating at OSLO Airport Gardermoen, The IEA 8th Heat Pump Conference, Las Vegas, USA, May 2006.
5. Katarzyna Zwarycz, Snow melting and heating systems based on geothermal heat pumps at Goleniow Airport Poland, Geothermal Training Programme Reports, The United Nations University, Iceland, 2002.