"Energiebronnen." . . "Ressources énergétiques." . . "Energiequelle." . . "Relatie energie-economie." . . . . "Alternatieve technologie." . . . . . . . . . . . . . . . "Chigu wa mul kwa param kwa t'aeynag : uri ŭi enŏji taep'yo" . . . . "地球와물과바람과太陽 : 우리의에너지代案" . . . . . . . "Discusses energy sources that are possible substitutes for fossil fuels, including geothermal power, water power, wind and solar energy." . . . "Earth, water, Wind, and sun : our energy alternatives" . . "Earth, water, wind, and sun, our energy alternatives"@en . "Earth, water, wind, and sun, our energy alternatives" . . "Energy from the earth; The energy crisis is real; Geothermal energy; Energy from water; Waterpower; Tidal power; Sea thermal energy; Energy from the wind and sun; Power from the wind; Biofuels: the renewable supply; Solar energy; Crossroads for energy." . . "Earth, water, wind, and sun our energy alternatives" . . . . . . . . "Earth, water, wind, and sun : our energy alternatives" . . "Sources d'énergie." . . "Alternativ energi" . . "Harper & Row" . . "Duurzame energie." . . "Economische aspecten." . .