Columbia subject headings:
Harbors--Italy--Porto Empedocle--History--20th century--Pictorial works.
Porto Empedocle (Italy)--Commerce--History--20th century--Pictorial works.
Porto Empedocle (Italy)--History--20th century--Pictorial works.
Harvard subject headings:
Porto Empedocle (Italy)--Economic conditions--20th century.
Porto Empedocle (Italy)--History--20th century.
Porto Empedocle (Italy)--Pictorial works.
Porto Empedocle--Economic conditions--20th century.
Princeton subject headings: