Columbia subject headings:
Harvard subject headings:
Cooperation--Italy--Ravenna (Province)--History--20th century.
Cooperative societies--Italy--Ravenna (Province)--History--20th century.
Federazione delle cooperative della Provincia di Ravenna--History.
Princeton subject headings:
Cooperation--Italy--Ravenna--History--20th century.
Cooperative societies--Italy--Ravenna--History--20th century.
Ravenna (Italy)--History--20th century.