1. Directive. 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 and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC. s.l. : 〈http://eur-lex.europa.eu/legal-content/EN/ALL/;ELX_SESSIONID=S3wXJkTDln6bTVmDxnz3HBWSGbLYvDxsp7XnpTmr3SQ55L152jfh!-2003075577?uri=CELEX:32009L0028〉, 2009/28/EC.
2. EUCO169/14. European Council (23 and 24 October 2014). Conclusions on 2030 Climate and Energy Policy Framework, accessible at http://www.consilium.europa.eu/uedocs/cms_data/docs/pressdata/en/ec/145397.pdf.
3. The analysis on photovoltaic electricity generation status, potential and policies of the leading countries in solar energy;Dincer;Renew Sustain Energy Rev,2011
4. Indicators for energy security;Kruyt;Energy Pol,2009
5. Composite indicators for security of energy supply using ordered weighted averaging;Costescu Badea;Reliab Eng Syst Safe,2011