8Hewitt NJ, McMullan JT, Mongey B, Some aspects of using hydrocarbons as components in refrigerant mixtures. New applications of natural working fluids in refrigeration and air conditioning, Hannover, Germany: IIR Commission B2,1994.
9Krauss R,Stephan K, Literature survey on thermophysical properties of natural refrigerants, Proc: IIF/IIR Gustav Lorenzen Conf., Oslo. Norway, 1998.
10Nowacki JE,Safety with flammable refrigerants, Report no 7 for NUTEK program "Alternative Refrigerants", Royal Institute of Technology, Applied Thermodymmics and Refrigeration, Stockholm. Sweden, 1995.