Columbia subject headings:
Harvard subject headings:
Left-wing extremists--Congresses.
Left-wing extremists--Germany--Congresses.
Linkspartei (Germany)--Congresses.
Radicalism--Congresses
Radicalism--Germany--Congresses.
Princeton subject headings:
Left-wing extremists--Congresses.
Left-wing extremists--Germany--Congresses.
Linkspartei (Germany)--Congresses.
Radicalism--Congresses.
Radicalism--Germany--Congresses.