1. BP Statistical Review of World Energy 2020;British Petroleum,2020
2. U.S. Energy Information Administration’s (EIA’s) Annual Energy Outlook 2014,2014
3. https://www.energy-transition-institute.com/documents/17779499/17781888/Summary+Introduction+to+Natural+Gas-ENG.pdf/f054f8fb-3a2c-a458-1e26-e8330a0a6f3f?t=1554800318222.
4. Greenhouse-gas emission targets for limiting global warming to 2 °C
5. Evidence-Based Clim. Sci. Data Opposing CO2 Emiss. As Prim. Source Glob. Warm;Easterbrook,2016