Columbia subject headings:
Biomass energy industries.
Energy industries--Vocational guidance.
Geothermal resources.
Hydroelectric power plants.
Renewable energy sources--Economic aspects.
Solar energy industries.
Wind power industry.
Harvard subject headings:
Biomass energy industries.
Energy industries--Vocational guidance.
Geothermal resources.
Hydroelectric power plants.
Renewable energy sources--Economic aspects.
Solar energy industries.
Wind power industry.
Princeton subject headings: