Columbia subject headings:
Electric utilities--Rates--United States.
Natural gas--Rates--United States.
Natural gas--United States--Rates.
Petroleum products--Prices--United States.
Harvard subject headings:
Electric utilities--Rates--United States.
Natural gas--Rates--United States
Petroleum products--Prices--United States
Princeton subject headings:
Electric utilities--Rates--United States.
Natural gas--Rates--United States.
Petroleum products--Prices--United States.