1. Thermal use of the Underground – Fundamentals, Approvals, Environmental Aspects;Verein Deutscher Ingenieure (VDI 4640 Part 1),2000
2. Increasing confidence in geothermal heat pump design methods;Shonder,1998
3. A New Comparison of Vertical Ground Heat Exchanger Design Methods for Residential Applications;Shonder,1999
4. Impact of grout thermal conductivity on the long-term efficiency of the ground-source heat pump system;Kurevija;Sustain. Cities Soc.,2017
5. Improving the thermal performance of coaxial borehole heat exchangers;Zanchini;Energy,2010