1. Global Status Reporthttp://www.ren21.net/wp-content/uploads/2018/06/17-8652_GSR2018_FullReport_web_final_.pdf
2. European Commission COMMISSION REGULATION (EU) 2017/1485—of 2 August 2017—Establishing a Guideline on Electricity Transmission System Operationhttp://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32017R1485&from=EN
3. World Energy Council World Energy Resources E-Storage 2016https://www.worldenergy.org/wp-content/uploads/2017/03/WEResources_E-storage_2016.pdf