Columbia subject headings:
Harvard subject headings:
Air--Pollution--Law and legislation--United States
Coal trade--Government policy--United States.
Fossil fuels--Environmental aspects--United States.
Fossil fuels--United States--Costs.
Industries--United States--Power supply--Decision making.
Princeton subject headings:
Air--Pollution--Law and legislation--United States.
Coal trade--Government policy--United States.
Fossil fuels--Environmental aspects--United States.
Fossil fuels--United States--Costs.
Industries--Power supply--United States--Decision making.