Columbia subject headings:
Harbors--Security measures--United States.
Harbors--United States--Foreign ownership.
Marine terminals--Security measures--United States.
National security--United States.
Shipping--Security measures--United States.
Harvard subject headings:
Harbors--Security measures--United States
Harbors--United States--Foreign ownership.
Marine terminals--Security measures--United States.
National security--United States
Shipping--Security measures--United States
Princeton subject headings:
Harbors--Security measures--United States.
Harbors--United States--Foreign ownership.
Marine terminals--Security measures--United States.
National security--United States.
Shipping--Security measures--United States.