1. S. P. Filippov, “Development of the Centralized Heat Supply in Russia,” Teploenergetika, No. 12, 2–14 (2009) [Thermal Engineering, No 12, (2009)].
2. “Housing and Household Servicing of Population in Russia. 2010,” Statistical collection (Rosstat, Moscow, 2010) [in Russian].
3. http://www.energysavers.gov/your-home/space-heating-cooling/index.cfm/mytopic= 12640 .
4. J. Lund, B. Sunner, L. Rybach, et. al, “Geothermal (Ground-Source) Heat Pumps: a World Overview,” GHC Bull., No. 9, 1–10 (2004).
5. SNiP 23-01-99*, “Construction Climatology” (State Standard) (Gosstroi Rossii, Moscow, 2003).