Columbia subject headings:
Harvard subject headings:
Developing countries--Commercial policy--Econometric models.
Developing countries--Foreign economic relations.
Duty-free importation--Developing countries--Econometric models.
Non-tariff trade barriers--Developing countries--Econometric models.
Tariff preferences--Developing countries--Econometric models.
Tariff--Developing countries--Econometric models.
Princeton subject headings:
Duty-free importation--Developing countries.
Free trade--Developing countries.
Protectionism--Developing countries.