1. Department of Petroleum Resources (DPR), Nigeria Gas Resources and Investment Opportunities, 2003 DPR report.
2. Why we must turn to gas;Egbert;Nigeria Oil and Gas Monthly (Journal),1998
3. Natural Gas for Sustainable Development;Elisabetta,2009
4. Energy Information Administration, International Energy Annual 2006. http//www.eia.doe.gov/iea/ng.html
5. Oilfield Review, Turning natural gas into liquid, 2003 http://www.slb.com/media/services/resources/oilfieldreview/ors03/aut03/p32_37.pdf.