1. Innovation Landscape Brief: Net Billing Schemes
https://irena.org//media/Files/IRENA/Agency/Publication/2019/Feb/IRENA_Net_billing_2019.pdf?la=en&hash=DD239111CB0649A9A9018BAE77B9AC06B9EA0D25
2. Country Profiles
https://www.irena.org/Statistics/View-Data-by-Topic/Renewable-Energy-Balances/Country-Profiles
3. Energy from Renewable Sources in 2019;GUS
4. Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections;Feldman,2012
5. Tracking the Sun X: The Installed Price of Residential and Non-Residential Photovoltaic Systems in the United States;Barbose,2017