1. Membranes for natural gas sweetening and CO2 enrichment;Mazur;Chem. Eng. Prog.,1982
2. W.J. Koros, R.T. Chern, Separation of gaseous mixtures using polymer membranes, in: R. Rosseau (Ed.), Handbook of Separation Process Technology, Chapter 20, Wiley, New York, 1987, p. 862
3. L.C.E. Struik, Physical Ageing in Amorphous Polymers and Other Materials, Elsevier, Amsterdam, 1978
4. An overview of the nonequilibrium behaviour of polymer glasses;Tant;Polym. Eng. Sci.,1981
5. Physical ageing of polymers;Hutchinson;Prog. Polym. Sci.,1995