1. International Renewable Energy Agency https://www.irena.org/‐/media/Files/IRENA/Agency/Publication/2019/Nov/IRENA_Future_of_Solar_PV_2019.pdf(accessed: July2019).
2. World Economic Forum Renewable Infrastructure Investment Handbook: A guide for Institutional Investors http://www3.weforum.org/docs/WEF_Renewable_Infrastructure_Investment_Handbook.pdf(accessed: July 2020).
3. A review of solar photovoltaic levelized cost of electricity
4. S.Philipps W. Warmuth Photovoltaics Report Fraunhofer Institute for Solar Energy Systems https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Photovoltaics‐Report.pdf(accessed: July2019).
5. Commercial progress and challenges for photovoltaics