1. IEA World Energy Outlook 2010;IEA,2010
2. IEA World Energy Outlook 2011;IEA,2011
3. World shale gas resources: an initial assessment of 14 regions outside the United States;DOE/EIA,2011
4. Assessing shale gas potential. Petroleum Review;Weijermars,2011
5. EU natural gas demand: uncertainty, dependence and bargaining power;Christie,2011