1. J.L. Barden, A.M. Fawi, P.D. Martin, V.V. Zaretskaya, International Energy Outlook, Washington, DC, DOE/EIA-0484 (2010). p.41.
2. H.S. Meyer, M. Henson, Technical report, Massachusetts university, 2002 1-10.
3. Natural Gas Processing with Membranes: An Overview
4. K.A. Lokhandwala, M. Ringer, H. Wijmans, R.W. Baker, Technical report, 1999.
5. Elsevier Science and Technology Series 4;Burggraaf,1996