Columbia subject headings:
Harvard subject headings:
Civil defense--United States
Computer networks--Security measures--United States
Computer security--United States--Planning.
Public utilities--Protection--United States.
Terrorism--Government policy--United States
Terrorism--United States--Prevention
Princeton subject headings:
Civil defense--United States.
Computer networks--Security measures--United States.
Computer security--United States--Planning.
Public utilities--Protection--United States.
Terrorism--Government policy--United States.
Terrorism--United States--Prevention.