Columbia subject headings:
Civilization, Medieval--12th century.
Eleventh century.
Normans--Italy--Sicily--History.
Sicily (Italy)--History--1016-1194.
Harvard subject headings:
Normans--Italy--Sicily.
Sicily (Italy)--History--1016-1194
Princeton subject headings:
Normans--Italy--Sicily.
Sicily (Italy)--History--1016-1194.