1. DOE Office of Energy Efficiency and Renewable Energy 2008 http://www1.eere.energy.gov/windandhydro/pdfs/41869.pdf
2. American Wind Energy Association 2009 http://www.awea.org/pubs/documents/Outlook_2009.pdf
3. United States General Accounting Office 1999 http://www.gao.gov/archive/1999/rc99130.pdf
4. IEC/TC88 1998 64100-1 wind turbine generator systems-part 1: safety requirements
5. Wind turbine control for load reduction;Bossanyi;Wind Energy,2003