Columbia subject headings:
Industries--Italy--Arno River Valley--History.
Labor disputes--Italy--Arno River Valley--History.
Working class--Italy--Arno River Valley--History.
Harvard subject headings:
Industries--Italy--Arno River Valley--History.
Labor disputes--Italy--Arno River Valley--History.
Working class--Italy--Arno River Valley--History.
Princeton subject headings:
Arno River Valley (Italy)--Politics and government.
Arno River Valley (Italy)--Social conditions.
Industries--Italy--Arno River Valley.