Columbia subject headings:
Harvard subject headings:
Aeronautics, Commercial--Security measures--United States
Aeronautics, Commercial--United States--Security measures.
Airports--Baggage handling--Safety regulations--United States.
Airports--Baggage handling--United States--Safety regulations.
Airports--Security measures--United States
Explosives--Detection--United States.
Princeton subject headings:
Aeronautics, Commercial--Security measures--United States.
Airports--Baggage handling--Safety regulations--United States.
Airports--Security measures--United States.
Explosives--Detection--United States.