1. The Earth Summit,1992
2. Kyoto protocol to the United Nations Framework Convention on Climate Change,1997
3. OECD environmental outlook,2001
4. EWEA/Greenpeace. Wind Force 12: a blueprint to achieve 12% of the world's electricity from wind power by 2020 European Wind Energy Association/Greenpeace, 2003.
5. EWEA/Greenpeace. Wind Force 10: a blueprint to achieve 10% of the world's electricity from wind power by 2020 European Wind Energy Association/Greenpeace, 1999.