Columbia subject headings:
Carolingians.
Customs administration--France--History.
France--Economic conditions.
Tariff--France--History.
Harvard subject headings:
Carolingians.
Customs administration--France--History.
France--Economic conditions.
Tariff--France--History.
Princeton subject headings:
Carolingians.
Customs administration--France--History.
Economic history--Medieval, 500-1500.
France--Economic conditions.
Tariff--France--History.