Columbia subject headings:
Energy industries--Security measures.
Petroleum industry and trade--Security measures--United States.
Petroleum reserves--Security measures.
Terrorism--United States--Prevention.
Harvard subject headings:
Energy industries--Security measures.
Petroleum industry and trade--Security measures--United States.
Petroleum reserves--Security measures.
Terrorism--United States--Prevention
Princeton subject headings:
Energy industries--Security measures.
Petroleum industry and trade--Security measures--United States.
Petroleum reserves--Security measures.
Terrorism--United States--Prevention.