Columbia subject headings:
Architecture, Medieval--Italy--Sicily.
Architecture, Norman--Italy--Sicily.
Islamic architecture--Italy--Sicily.
Palaces--Italy--Sicily.
Harvard subject headings:
Architecture, Medieval--Italy--Sicily.
Architecture, Norman--Italy--Sicily.
Islamic architecture--Italy--Sicily.
Palaces--Italy--Sicily.
Princeton subject headings:
Architecture, Medieval--Italy--Sicily.
Architecture, Norman--Italy--Sicily.
Islamic architecture--Italy--Sicily.
Palaces--Italy--Sicily.