Columbia subject headings:
Gas industry--United States.
Natural gas reserves--United States.
Natural gas--Prospecting--Government policy--United States.
Harvard subject headings:
Gas industry--United States
Natural gas reserves--United States.
Natural gas--Prospecting--Government policy--United States.
Princeton subject headings:
Gas industry--United States.
Natural gas reserves--United States.
Natural gas--Prospecting--Government policy--United States.