1. World Wind Energy Association, Report 2011; 2012.
2. European Wind Energy Association, wind in power. European Statistics; 2012.
3. European Wind Energy Association, Pure Power. Wind energy targets for 2020 and 2030; 2009.
4. Wind energy explained. theory, design and application;Manwell,2009
5. Wind energy: fundamentals, resource analysis and economics;Mathew,2006