Columbia subject headings:
Agriculture and state.
Conservation of natural resources--Government policy.
Economic policy.
Energy policy.
Food supply--Government policy.
Forest policy.
Population policy.
Harvard subject headings:
Agriculture and state.
Conservation of natural resources--Government policy.
Economic policy.
Energy policy
Food supply--Government policy.
Forest policy.
Population policy.
Princeton subject headings:
Energy conservation.
Energy policy.
Environmental policy.
Environmental protection.