1. The use of natural refrigerants: a complete solution to the CFC/HCFC predicament;Lorentzen;Int. J. Refrig,1995
2. Robinson D, Groll E. Using carbon dioxide in a transcritical vapor compression refrigeration cycle. Sixth International Refrigeration Conference, Purdue University, 25 July 1996.
3. Wertenbach J, Kauf F. High pressure refrigeration system with CO2 in automobile air conditioning. CO2 Technology in Refrigeration, Heat Pump and Air Conditioning Systems, NTNU-Trondheim, 13–14 May 1997.
4. Gentner H. Passenger car air conditioning using carbon dioxide as refrigerant. Conference on Natural Working Fluids, Oslo, Norway, 2–5 June 1998.
5. Wertenbach J, Caesar R. An environmental evaluation of an automobile air conditioning system with CO2 versus HFC-134a as refrigerant. Conference on Natural Working Fluids, Oslo, Norway, 2–5 June 1998.