Columbia subject headings:
Harvard subject headings:
Conservatism--Europe
European Union countries--Politics and government.
Radicalism--European Union countries.
Right and left (Political science)--Europe.
Totalitarianism
Princeton subject headings:
Assimilation (Sociology)--Europe.
Europe--Ethnic relations.
Europe--Politics and government.
European Union--Ethnic relations.
Extremists.
Left-wing extremists.
Radicalism--Europe.
Radicals.
Right-wing extremists.
Social problems--Europe--21st century.