1. U.S. Energy Information Administration. Residential Energy Consumption Survey (RECS). http://www.eia.gov/consumption/residential/data/2009/index.cfm?view=consumption (seen on 06/02/2014).
2. U.S. Energy Information Administration. Annual Energy Review 2011. http://www.eia.gov/totalenergy/data/annual/diagram1.cfm (seen on 06/02/2014).
3. Safeguarding the Ozone Layer and the Global Climate System;IPCC/TEAP Special Report,2005
4. Ozone depletion and global warming: case for the use of natural refrigerant – a review;Bolaji;Renew. Sustain. Energy Rev.,2013
5. Optimal control of the gas-cooler pressure of a CO2 heat pump using EEV opening and outdoor fan speed in the cooling mode;Baek;Int. J. Refrig.,2013