1. Energy roadmap 2050;European Commission,2012
2. 2050 low-carbon economy;European Commission,2016
3. Eurostat, energy, transport and environmental indicators,2013
4. Climate change 2014: mitigation of climate change;IPCC,2014
5. Directive 2012/27/EU, Directive 2012/27/EU of the European Parliament and of the Council of 25 October 2012 on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU and repealing Directives 2004/8/EC and 2006/32/EC.