1. Union of Concerned Scientists, https://www.ucsusa.org/energy/renewable-energy.
2. The Global Wind Energy Council (GWEC), http://gwec.net/publications/global-wind-report-2/.
3. GWEC Global Wind Statistics 2014, https://www.gwec.net/wp-content/uploads/2015/02/GWEC_GlobalWindStats2014_FINAL_10.2.2015.pdf.
4. GL 2010, Guideline for the Certification of Wind Turbines, Germanischer Lloyd Industrial Services GmbH, 2010.
5. GL Wind 2005, Guideline for the Certification of Offshore Wind Turbines, Germanischer Lloyd Industrial Services GmbH, 2005.