Columbia subject headings:
Industries--Italy--Ravenna--History.
Ravenna (Italy)--Economic conditions.
Ravenna (Italy)--Politics and government.
Ravenna (Italy)--Social conditions.
Harvard subject headings:
Ravenna (Italy)--Economic conditions--19th century.
Ravenna (Italy)--Economic conditions--20th century.
Ravenna (Italy)--Politics and government--19th century.
Ravenna (Italy)--Politics and government--20th century.
Ravenna (Italy)--Social conditions--19th century.
Ravenna (Italy)--Social conditions--20th century.
Princeton subject headings:
Ravenna (Italy)--Economic conditions--19th century.
Ravenna (Italy)--Economic conditions--20th century.
Ravenna (Italy)--Politics and government--19th century.
Ravenna (Italy)--Politics and government--20th century.
Ravenna (Italy)--Social conditions--19th century.
Ravenna (Italy)--Social conditions--20th century.