Columbia subject headings:
Church architecture--Italy--Bologna (Province)
Church bells--Italy--Bologna (Province)--History.
Towers--Italy--Bologna (Province)
Harvard subject headings:
Bell towers--Italy--Bologna (Province)
Bell towers--Italy--Bologna.
Church architecture--Italy--Bologna (Province)
Church architecture--Italy--Bologna.
Church bells--Italy--Bologna (Province)--History.
Church bells--Italy--Bologna--History.
Towers--Italy--Bologna (Province)
Princeton subject headings:
Bell towers--Italy--Bologna (Province).
Church bells--Italy--Bologna (Province).