Columbia subject headings:
Harvard subject headings:
Agriculture and state--United States.
Agriculture--Developing countries
Agriculture--Economic aspects--United States
Developing countries--Commerce--United States.
Produce trade--United States
United States--Commerce--Developing countries.
Princeton subject headings:
Agriculture and state--United States.
Agriculture--Developing countries.
Agriculture--Economic aspects--United States.
Developing countries--Commerce--United States.
Produce trade--United States.
United States--Commerce--Developing countries.