1. Kyoto Protocol to the United Nations Framework - Convention on Climate Change,1998
2. Council Decision of 25 April 2002 concerning the approval, on behalf of the European Community, of the Kyoto Protocol to the United Nations Framework Convention on Climate Change and the joint fulfilment of commitments thereunder (2002/358/CE).
3. Directive 2009/28/EC of the european parliament and of the council of 23 April 2009 on the promotion of the use of energy from renewable sources.
4. A Policy Framework for Climate and Energy in the Period from 2020 to 2030,2014
5. https://www.epa.gov/cleanpowerplan.