1. SEIA/GTM Research: U.S. Solar Market®, Q3 2015, Executive Summary
2. Global Market Outlook for Solar Power, 2015-2019, Solar Power Europe
3. Staff writer, Pricing Sunshine, The Economist, Retrieved 2012-12-28
4. Photovoltaics Report, Fraunhofer Institute for Solar Energy Systems, ISE, 2015
5. S. Abermann, Sol. Energy 94, 37–70 (2013)