US6695973-B1  Didion, D. A. and D. B. Bivens May 1990, "Role of refrigerant mixtures as alternatives to CFCs," Int. J. Refrig., vol. 13, p. 163-168.US42652-E  D.A. Didion and D.B. Bivens_Role of refrigerant mixtures as alternatives to CFCs._International Journal of Refrigeration, 1990, vol. 13, p. 163-175.;  D. Butler_R22 drop-in a success at BRE_Refrigeration and Air conditioning. Sep. 1994, 49-50.;  S.F. Pearson_Use of hydrocarbon refrigerants_IIF IIR Commisions B1, B2, El, and E2_Aarthus Denmark 1996-3, p. 439-446.;  N. A. Roberts and S.F. Pearson_High efficiency R22 replacement (ISCEON 59, a mixture or RF125, R134a and isobutane)_US 1996 Pap. 1996 Int. Compressor Eng. Conf. Purdue, Jul. 23-26, 1996.;  N. A. Roberts and S.F. Pearson_High efficiency R22 replacement_US 1996 Pap. 1996 Int. Compressor Eng. Conf. Purdue, Jul. 1996.;  Cesare Soffientini, Mark W. Spatz, Samuel Yana Motta, Elizabet Vera Becerra_CENTRO Studi Galilieo_Industria&Formazione_"Evaluation of Alternative Refrigerants When Retrofitting R-22 Refrigeration Systems"_11th European Conference Milan Jun. 17/18, 2005.;  Fluorocarbon Azeotropes_Research Disclosure 16265, Oct. 1977.;  N.A. Roberts_Determination of the performance, leak scenario, flammability and oil return characteristics of novel R22 replacement_Proceedings of the 1998 International Refrigeration Conference Purdue_E.A. Broil and J.E. Braun Editors_pp. 25-30, Jul. 1998.;  N.A. Roberts_Energy Saving Refrigerant blends comprising R125, R134A, R600 or R600a_European Conference Milane pp. 1-9, Jun. 7-8, 2005.;  Test Protocol for determination of Refrigerant properties.;  ASHRAE Standard 34-2001, Designation and Safety Classification of Refrigerants, pp. 7 and 13, 2001.;  Kuehn Birett_Merkblaetter Gefaehrliche Arbeits-Stoffe_94 Erg. Lfg., B037-1-B037-2 and B060-1-2, Dec. 1996.;  David P Wilson et al., Determination of Refrigerant Lower Flammability Limits in Compliance with Proposed Addendum p to Standard 34,_Ashrae Transaction Symposia, 739-756, 2001.;  D17 Test Protocol for determination of Refrigerant properties dated Mar. 30, 2006.;  Didion, D. A. and D. B. Bivens May 1990, "Role of refrigerant mixtures as alternatives to CFCs," Int. Refrig., vol. 13, p. 163-168.