Columbia subject headings:
Geothermal engineering--Congresses.
Geothermal resources--Congresses.
Steam power plants--Congresses.
Harvard subject headings:
Geothermal engineering--Congresses
Geothermal resources--Congresses
Steam power-plants--Congresses.
Princeton subject headings:
Geothermal engineering--Congresses.
Geothermal resources--Congresses.
Steam power plants--Congresses.