Columbia subject headings:
Harvard subject headings:
Agriculture--Economic aspects--Italy, Northern--History.
Agriculture--Economic aspects--Italy--Bologna (Province)--History.
Bologna (Italy : Province)--Economic conditions.
Bologna (Italy : Province)--Social conditions.
Church lands--Italy, Northern--History--To 1500.
Italy, Northern--Economic conditions.
Italy, Northern--Population--History.
Italy, Northern--Social conditions.
Land use--Italy, Northern--History--To 1500.
Land use--Italy--Bologna (Province)--History--To 1500.
Water use--Italy, Northern--History--To 1500.
Princeton subject headings:
Church lands--Italy, Northern--History--To 1500.
Land use--Italy, Northern--History--To 1500.
Land use--Italy--Bologna (Province)--History--To 1500.
Water use--Italy, Northern--History--To 1500.