Columbia subject headings:
Harvard subject headings:
Europe--Economic integration--Political aspects--History--20th century.
Europe--Economic integration--Political aspects--History--21st century.
Political participation--Europe--History--20th century.
Political participation--Europe--History--21st century.
Princeton subject headings:
Europe--Economic integration--Political aspects--History--20th century.
Europe--Economic integration--Political aspects--History--21st century.
Political participation--Europe--History--20th century.
Political participation--Europe--History--21st century.