1. Natural gas: a presentation by the Bureau of Economic Geology at the University of Texas, Austin; 2000. .
2. Simmons M. Interview behind the blackout; 2003. .
3. Innovation – the attacker’s advantage;Foster,1986
4. World natural gas endowment as a bridge towards zero carbon emissions;Aguilera;Technol Forecasting Soc Change,2012
5. The GET – grand energy transition;Heffner,2008