Columbia subject headings:
Harvard subject headings:
Agriculture and state--United States.
Agriculture and state.
Agriculture--Economic aspects
Agriculture--Economic aspects--United States
International economic relations
Produce trade--Government policy
Produce trade--Government policy--United States
Princeton subject headings:
Agriculture and state--United States.
Agriculture and state.
Agriculture--Economic aspects--United States.
Agriculture--Economic aspects.
International economic relations.
Produce trade--Government policy--United States.
Produce trade--Government policy.