1. World Energy Outlook, Int. Energy Agency, 2008. http://www.iea-pvps.org
2. Pachauri, R.K., World Sustainable Development Forum, New Delhi: Energy and Resources Institute, 2007.
3. Communication from the Commission to the Council and the European Parliament; Renewable Energy Road Map — Renewable energies in the 21st century: building a more sustainable future; COM (2006) 848final (07.01.2007), {SEC (2006) 1719; SEC (2006) 1720; SEC (2007) 12}. http://europa.eu/
4. Global Market Outlook for Photovoltaics until 2013, European Photovoltaic Industry Association. http://europa.eu/
5. Renewable Energy Targets for Europe: 20% by 2020, European Renewable Energy Council. http://europa.eu/