1. Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment;ASHRAE Standard 37-2005,2005
2. Methods of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps;ANSI/ASHRAE Standard 116-2010,2010
3. Two-stage air-source heat pump for residential heating and cooling applications in northern US climate;Bertsch;Int. J. Refrigeration,2008
4. Cawley, R.E., 2003. Replacement refrigerant for R410A. U.S. Patent, No. 0057396 A1.
5. IPCC Fourth Assessment Report;Climate Change Synthesis Report,2007