Columbia subject headings:
Farm produce--Economic aspects.
Farm produce--Government policy.
Farm produce--Quality--Government policy.
Farm produce--Sanitation--Government policy.
Non-tariff trade barriers.
Harvard subject headings:
Princeton subject headings:
Farm produce--Economic aspects.
Farm produce--Government policy.
Farm produce--Quality--Government policy.
Farm produce--Sanitation--Government policy.
Non-tariff trade barriers.