Columbia subject headings:
Harvard subject headings:
Bin Laden, Osama, 1957-2011.
International relations and terrorism.
Qaida (Organization)--History.
September 11 Terrorist Attacks, 2001
Terrorism--History--21st century.
Princeton subject headings:
Qaida (Organization)--History.
Terrorism--History--20th century.
Terrorism--History--21st century.