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The generalized system of preferences and the multilateral trade negotiations : study by the UNCTAD secretariat
(1978)
Trade preferences for less-developed countries : an analysis of United States policy
Weintraub, Sidney, (1967)
The tariff preference : a reconsideration
Katz, Sherman E., (1971)
Testing the USA generalized system of preferences
Pantelides, Pantelis, (1984)