Columbia subject headings:
Deep ecology--United States.
Environmentalism--United States.
Sabotage--United States.
Terrorism--United States.
Harvard subject headings:
Deep ecology--United States.
Ecoterrorism--United States.
Environmentalism--United States
Sabotage--United States
Terrorism--United States
Princeton subject headings:
Deep ecology--United States.
Environmentalism--United States.
Sabotage--United States.
Terrorism--United States.