IEA (2021), Share of energy companies that obtained seed-stage funding in 2010 that obtained follow-on funding, by technology area, IEA, Paris https://www.iea.org/data-and-statistics/charts/share-of-energy-companies-that-obtained-seed-stage-funding-in-2010-that-obtained-follow-on-funding-by-technology-area, Licence: CC BY 4.0