1. EU Strategy on Heating and Cooling, SWD 24 final report (European Commission Brussel, 2016)
2. European Heat Pump Statistics, The European Heat Pump Association (EHPA), Brussels, 2009
3. DISTRICT ENERGY IN CITIES, Unlocking the Potential of Energy Efficiency and Renewable Energy (UNEP, Paris 2015)
4. Dagilis V., Vaitkus L., Combined heat pump and water-power plant at Kaunas Lagoon, The 9th International Conference ENVIRONMENTAL ENGINEERING, Vilnius, Lithuania 2014