Columbia subject headings:
Non-tariff trade barriers.
Organisation for Economic Co-operation and Development.
Tariff.
Harvard subject headings:
Non-tariff trade barriers--OECD countries.
Non-tariff trade barriers.
Organisation for Economic Co-operation and Development
Tariff--OECD countries.
Tariff.
Princeton subject headings:
Non-tariff trade barriers.
Organisation for Economic Co-operation and Development.
Tariff.