Columbia subject headings:
Emergency management--United States--Planning.
Local transit--Security measures--United States.
London Terrorist Bombings, London, England, 2005.
Terrorism--United States--Prevention.
Transportation--Security measures--United States.
Harvard subject headings:
Emergency management--United States--Planning.
Local transit--Security measures--United States.
London Terrorist Bombings, London, England, 2005.
Terrorism--United States--Prevention
Transportation--Security measures--United States
Princeton subject headings:
Emergency management--United States--Planning.
Local transit--Security measures--United States.
London Terrorist Bombings, London, England, 2005.
Terrorism--United States--Prevention.
Transportation--Security measures--United States.