Columbia subject headings:
Metal trade--United States.
Metal trade.
Mines and mineral resources--United States.
Mines and mineral resources.
National security--United States.
Strategic materials--United States.
Strategic materials.
Harvard subject headings:
Metal trade--United States
Metal trade.
Mines and mineral resources--United States
Mines and mineral resources.
National security--United States
Strategic materials
Strategic materials--United States
Princeton subject headings:
Metal trade--United States.
Metal trade.
Mines and mineral resources--United States.
Mines and mineral resources.
National security--United States.
Strategic materials--Government policy--United States.
Strategic materials.