1. British Petroleum (BP), Statistical Review of World Energy, 68th edn, 2019, accessed: 10/02/2021, https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-full-report.pdf
2. Estimation of global final-stage energy-return-on-investment for fossil fuels with comparison to renewable energy sources
3. Shell, World Energy Model – A View To 2100, 2017, accessed: 10/02/2021, https://www.shell.com/energy-and-innovation/the-energy-future/scenarios/shell-scenarios-energy-models/world-energy-model/_jcr_content/par/textimage.stream/1510344160326/2ee82a9c68cd84e572c9db09cc43d7ec3e3fafe7/shell-world-energy-model.pdf
4. International Energy Agency (IEA), Global Energy Review 2019, IEA, Paris, 2020, accessed: 10/02/2021, https://www.iea.org/reports/global-energy-review-2019
5. REN 21, 2019, Renewables 2019 Global Status Report, Paris: REN21 Secretariat, ISBN 978-3-9818911-7-1