Columbia subject headings:
Harvard subject headings:
Communists--Germany--Biography--Congresses.
Feminists--Germany--Biography--Congresses.
Zetkin, Klara, 1857-1933--Congresses.
Princeton subject headings:
Communists--Germany--Biography--Congresses.
Feminists--Germany--Biography--Congresses.
Zetkin, Klara, 1857-1933--Congresses.