Columbia subject headings:
Normans--Italy--Sicily--Congresses.
Sicily (Italy)--History--1194-1282--Congresses.
Harvard subject headings:
Normans--Italy--Sicily--Congresses.
Sicily (Italy)--History--1194-1282--Congresses.
Princeton subject headings:
Italy, Southern--History--Congresses.
Sicily (Italy)--History--1016-1194--Congresses.
Sicily (Italy)--History--1194-1282--Congresses.