IEA, Change in the share of coal in fossil fuel power generation and change in the gas price in the United States, 2010-2018, IEA, Paris https://www.iea.org/data-and-statistics/charts/change-in-the-share-of-coal-in-fossil-fuel-power-generation-and-change-in-the-gas-price-in-the-united-states-2010-2018, Licence: CC BY 4.0