1. Appliance Magazine, Japanese Heat-Pump Water Heater Market Growing; September 2005, p. 20.
2. ASHRAE Standard 118.2, Method of Testing for Rating Residential Water Heaters;ASHRAE,2006
3. Carbon dioxide as refrigerant for tap water heat pumps: a comparison with the traditional solution;Cecchinato;International Journal of Refrigeration,2005
4. Effects of refrigerant charge amount on the performance of a transcritical CO2 heat pump;Cho;International Journal of Refrigeration,2005
5. Technology and market development of CO2 heat pump water heaters (ECO Cute) in Japan;Hashimoto;IEA Heat Pump Centre Newsletter,2006