Columbia subject headings:
Tourism--Italy--Lombardy--History.
Tourism--Italy--Lombardy.
Harvard subject headings:
Lombardy (Italy)--Economic conditions.
Tourism--Italy
Tourism--Italy--History--19th century.
Tourism--Italy--History--20th century.
Tourism--Italy--Lombardy--History.
Tourism--Italy--Lombardy.
Princeton subject headings:
Tourism--Economic aspects--Italy.
Tourism--Italy--History--19th century.
Tourism--Italy--History--20th century.