Columbia subject headings:
Mary, Blessed Virgin, Saint--Art.
Mercy, Our Lady of--Devotion to--Italy--Emilia-Romagna--History--To 1500.
Harvard subject headings:
Christian art and symbolism--Italy--Bologna--Medieval, 500-1500.
Christian art and symbolism--Italy--Romagna--Medieval, 500-1500.
Mary, Blessed Virgin, Saint--Art.
Princeton subject headings:
Art.
Mary, Blessed Virgin, Saint--Art.
Mercy, Our Lady of--Devotion to--Italy--Emilia-Romagna--History--To 1500.