Columbia subject headings:
Commerce--History--To 1500.
Commodity exchanges--History.
Raw materials--History.
Harvard subject headings:
Commerce--History--To 1500.
Commodity exchanges--History.
Raw materials--History.
Princeton subject headings:
Commerce--History--Medieval, 500-1500--Congresses.
Commerce--History--To 500--Congresses.
Raw materials--History--Congresses.