1. European parliament adopted the directive on the use of renewable energy sources;Seppänen;Rehva Journal,2009
2. Design methods for ground-source heat pumps;Ball;ASHRAE Transactions,1983
3. Theory of the ground pipe source for the heat pump;Ingersoll;ASHVE Transactions,1948
4. Ground-source Heat Pumps Design of Geothermal Systems for Commercial and Institutional Buildings;Kavanaugh,1997
5. Design/data Manual for Closed-loop Ground-coupled Heat pump Systems;Bose,1985