Columbia subject headings:
Harvard subject headings:
Commerce--History--Medieval, 500-1500
Europe--Commerce--Poland.
Europe--Foreign economic relations--Poland.
Europe--History--476-1492.
Piast dynasty.
Poland--Commerce--Europe.
Poland--Economic conditions
Poland--Foreign economic relations--Europe.
Poland--History--Piast period, 960-1386
Silver
Silver coins--Poland--History.
Princeton subject headings:
Commerce--History--Medieval, 500-1500.
Europe--History--476-1492.
Piast dynasty.
Silver.