Columbia subject headings:
Economic development--Environmental aspects.
Environmental protection--Western Hemisphere.
Free trade--Western Hemisphere.
Western Hemisphere--Economic policy.
Harvard subject headings:
America--Economic policy.
Economic development--Environmental aspects
Environmental protection--America.
Environmental protection--Western Hemisphere.
Free trade--America
Free trade--Western Hemisphere.
Western Hemisphere--Economic policy.
Princeton subject headings:
Economic development--Environmental aspects.
Environmental protection--Western Hemisphere.
Free trade--Western Hemisphere.
Western Hemisphere--Economic policy.