Columbia subject headings:
Bologna (Italy)--Commerce--History.
Bologna (Italy)--Economic conditions.
Bologna (Italy)--History--To 1506.
Harvard subject headings:
Bologna (Italy)--Commerce--History.
Bologna (Italy)--Economic conditions
Bologna (Italy)--History--To 1506
Commerce--History--Medieval, 500-1500
Merchants--Italy--Bologna--History.
Princeton subject headings:
Bologna (Italy)--Commerce--History.
Bologna (Italy)--Economic conditions.
Bologna (Italy)--History--To 1506.