https://www.globalwitness.org/documents/20405/Hydrogen_is_too_expensive_-_September_2022.pdf
https://advances.sciencemag.org/content/advances/6/14/eaay3539.full.pdf
http://advances.sciencemag.org/content/advances/3/7/e1602821.full.pdf
http://ec.europa.eu/invest-in-research/pdf/download_en/risk_management.pdf