Columbia subject headings:
Christian democratic parties--European Union countries--History.
European Union countries--Politics and government.
Political parties--European Union countries--History.
Right and left (Political science)--European Union countries--History.
Socialist parties--European Union countries--History.
Harvard subject headings:
European Union countries--Politics and government
Right and left (Political science)--European Union countries.
Socialist parties--European Union countries.
Princeton subject headings: