1. UNEP, Montreal protocol on substances that deplete the ozone layer, final act, New York: United Nations Environmental Program 1987
2. D. Butler, Life after CFCs and HCFCs, CIBSE National Conference, 2001
3. Comparative assessment of HFC 134a and some refrigerants as alternatives to CFC 12;Devotta;Int. J. Refrigeration,1992
4. Flammability of alternative refrigerants;Richards;ASHRE J.,1992
5. T.-J. Ritter, Flammability-hydrocarbon refrigerants, in: Proceedings of the Institute of Refrigeration Conference, Safe and Reliable Refrigeration, London, 1996