1. K. Wojdyga “Prediction of Heat Demand for District Heating Systems”, Publishing House of the Warsaw University of Technology, Warsaw, 2007.
2. “Heat in Numbers” report 2014, President of Energy Regulation Office, Warsaw, Poland.
3. K. Wojdyga, M.Chorzelski , “The hydraulic analyses for district heating system in Zielona Góra, Warsaw 2003. Research Center for Power and Environmental Protection, Warsaw University of Technology.” Research report (in polish-unpublished).
4. District Heating and Cooling Country by Country Survey 2013, B-1040 Brussels, Published by Euroheat & Power
5. K. Wojdyga, M. Chorzelski, “The methodology of estimation of heat losses from district heating pipes in Wroclaw” , Warsaw, 2002. Research Center for Power and Environmental Protection, Warsaw University of Technology. Research report (in Polish - unpublished).