1. API, 1959. Petroleum Facts and Figures. American Petroleum Institute.
2. Assessing the date of the global oil peak;Bentley;Energy Policy,2007
3. BP, 2010. Statistical Review of World Energy. Technical Report. BP.
4. BP, 2012. BP Energy Outlook 2030. Technical Report. BP.
5. The end of cheap oil;Campbell;Scientific American,1998