Combustibles fs̤iles 67 Fossil fuels Combustibles 64 Fuels 64 Industria del petrl̤eo 43 Petroleum industry 43 energa̕ 33 more ... energy 33 fuentes de energa̕ 33 energy sources 32 petrl̤eo 31 oil 30 petroleum 30 Industria petroqum̕ica 27 Petrochemical industry 27 gas natural 27 natural gas 27 Energy sources 18 Fuentes de energa̕ 18 Petrl̤eo 13 Energa̕ 12 Energy 11 Esquistos bituminosos 10 Shale oil 10 industria del petrl̤eo 10 oil industry 10 Oil 9 Petrl̤eo de esquisto 9 industria petroqum̕ica 9 petrochemical industry 9 less ...