Columbia subject headings:
City walls--Italy--Padua.
Padua (Italy)--Buildings, structures, etc.
Towers--Conservation and restoration--Italy--Padua.
Towers--Italy--Padua.
Harvard subject headings:
City walls--Italy--Padua.
Padua (Italy)--Buildings, structures, etc.
Towers--Conservation and restoration--Italy--Padua.
Towers--Italy--Padua.
Princeton subject headings:
City walls--Italy--Padua.
Padua (Italy)--Buildings, structures, etc.
Towers--Conservation and restoration--Italy--Padua.
Towers--Italy--Padua.