Columbia subject headings:
Harbors--Security measures--United States.
Marine terminals--Security measures--United States.
Terrorism--United States--Prevention.
Harvard subject headings:
Harbors--Security measures--United States
Marine terminals--Security measures--United States.
Terrorism--United States--Prevention
Princeton subject headings:
Harbors--Security measures--United States.
Marine terminals--Security measures--United States.
Terrorism--United States--Prevention.