1. International Energy Agency Solar https://www.iea.org/fuels-and-technologies/solar(accessed: May2020).
2. EU Market Outlook For Solar Power/2019–2023 https://www.solarpowereurope.org/wp-content/uploads/2019/12/SolarPower-Europe_EU-Market-Outlook-for-Solar-Power-2019-2023_.pdf?cf_id=10355(accessed: May2020).
3. Photovoltaics Report Fraunhofer Institute for Solar Energy Systems ISE with support of PSE Projects GmbH https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Photovoltaics-Report.pdf(accessed: May2020).
4. Organic Photovoltaics