Columbia subject headings:
Harvard subject headings:
European Union countries--Politics and government--21st century.
Partido Socialista Português.
Portugal--Politics and government--21st century.
Right and left (Political science)--European Union countries.
Socialism--European Union countries.
Socialism--Portugal.
Princeton subject headings:
European Union countries--Politics and government--21st century.
Right and left (Political science)--European Union countries.
Socialism--European Union countries.