Columbia subject headings:
Harvard subject headings:
Diesel fuels--Prices--United States.
Dwellings--Heating and ventilation--United States.
Petroleum as fuel--Prices--United States.
Petroleum industry and trade--United States
Princeton subject headings:
Diesel fuels--Prices--United States.
Dwellings--United States--Heating and ventilation.
Petroleum as fuel--Prices--United States.
Petroleum industry and trade--United States.