1. T Engler, L R Oellrich, S Srinivasa Murthy and G Venkatarathnam, Das VerhaltenzeotroperKohlenwasserstoffgemischeals FCKW-Alternativen in Waermepumpen, DKV-Tagungsbericht Hamburg, Vol.24, pp.260–277, 1997.
2. T Engler, L R Oellrich, S Srinivasa Murthy, G Venkatarathnam, and A R Balakrishnan, Refrigerant mixtures as alternatives to HCFC22 and R502, Forschungsberichte des DKV, No.54, 1996.
3. D A Didion and D B Bivens, Role of refrigerant mixtures as alternatives to CFCs, Int. J. Refrig., Vol.13, No.5, pp.163–175, 1990.
4. U Hesse, and H Arnemann, Carbon dioxide — hydrocarbon mixtures as alternative fluids in refrigeration systems, IIR Commission B2, Hannover, May 10–13, 1994.
5. N J Hewitt, J T McMullan and B Mongey, Some aspects of using hydrocarbons as components in refrigerant mixtures, IIR Commission B2, Hannover, May 10–13, 1994.