Ch. Tian and N. Liang, “State of Art of Air-Source Heat Pump for Cold Regions,” Proceedings of the 6th International Conference for Enhanced Building Operations, Shenzhen, 6-9 November 2006, Renewable Energy Resources and a Greener Future, Vol. VIII-12-5.
 J. Hayton, “Calculation Procedure for the SAP Appendix Q Process for Electrically Driven Heat Pumps,” 2010.
 N. Diao, Q. Li and Z. Fang, “Heat Transfer in Ground Heat Exchanger with Groundwater Advection,” International Journal of Thermal Sciences, Vol. 43, No. 12, 2004, pp. 1203-1211.
 O. Ozgener and A. Hepbasli, “Modeling and Performance Evaluation of Ground Source (Geothermal) Heat Pump Systems,” Energy and Buildings, Vol. 39, No. 1, 2007, pp. 66-75. http://dx.doi.org/10.1016/j.enbuild.2006.04.019
 Y. Nam, R. Ooka and S. Hwang, “Development of a Numerical Model to Predict Heat Exchange Rates for a Ground-Source Heat Pump System,” Energy and Buildings, Vol. 40, No. 12, 2008, pp. 2133-2140.
 V. R. Tarnawski, W. H. Leong, T. Momose and Y. Hamada, “Analysis of Ground Source Heat Pumps with Horizontal Ground Heat Exchangers for Northern Japan,” Renewable Energy, Vol. 34, No. 1, 2009, pp. 127-134.
 P. Cui, X. Li, Y. Man and Z. Fang, “Heat Transfer Analysis of Pile Geothermal Heat Exchangers with Spiral Coils,” Applied Energy, Vol. 88, No. 11, 2011, pp. 4113-4119.
 M. Li and A. C. K. Lai, “Heat-Source Solution to Heat Conduction in Anisotropic Media with Application to Pile and Borehole Ground Heat Exchangers,” Applied Energy, Vol. 96, 2012, pp. 451-458.
 S. Park, S.-R. Lee, H. Park, S. Yoon and J. Chung, “Characteristics of an Analytical Solution for a Spiral Coil Type Ground Heat Exchanger,” Computers and Geotechnics, Vol. 49, 2013, pp. 18-24.
 B. Poel, G. Cruchten, van A. Constantinos and A. C. Balaras, “Energy Performance Assessment of Existing Dwellings,” Energy and Buildings, Vol. 39, No. 4, 2007, pp. 393403. http://dx.doi.org/10.1016/j.enbuild.2006.08.008
 EN. Directive 2002/91/EC of the European Parliament and of the Council of 16 December 2002 on the Energy Performance of Buildings, “Official Journal of the European Communities,” Vol. 4, No. 1, 2003, pp. L1/65-L1/ 71.
 Ministry of Economic Affairs and Communications Ordinance No. 63, “Hoonete Energiatohususe Arvutamise Metoodika. (Methodology for Calculating the Energy Performance of Buildings) (08.10.2012); RT I, 18.10.2012, 1,” 2012.