1. 2030 Climate & Energy Frameworkhttp://ec.europa.eu/clima/policies/strategies/2030_en
2. Germany May Reach Its 2020 Target for Renewable Power This Yearhttp://reneweconomy.com.au/will-germany-reach-2020-target-renewable-power-year-74293/
3. Executive Order—Planning for Federal Sustainability in the Next Decade,2015
4. Renewable Energy in China: An Overview,2014