Columbia subject headings:
Harvard subject headings:
Gardens--Italy--Italy.
Gardens--Italy--Piacenza.
Palazzo Farnese (Piacenza, Italy)
Piacenza (Italy)--Buildings, structures, etc.
Piacenza (Italy). Musei civici.
Princeton subject headings:
Gardens--Italy--Piacenza.
Piacenza (Italy)--Buildings, structures, etc.
Piacenza (Italy). Musei civici