Columbia subject headings:
Palace of the Normans (Palermo, Italy)
Palaces--Italy--Palermo--History.
Palermo (Italy)--Buildings, structures, etc.
Harvard subject headings:
Architecture, Medieval--Italy--Palermo.
Palace of the Normans (Palermo, Italy)
Palermo (Italy)--Buildings, structures, etc.
Towers--Italy--Palermo.
Princeton subject headings:
Palace of the Normans (Palermo, Italy)
Palaces--Italy--Palermo--History.
Palermo (Italy)--Buildings, structures, etc.