Columbia subject headings:
Harvard subject headings:
Communism--Germany--History--20th century--Congresses.
Germany (East)--Politics and government--Congresses.
Kommunistische Partei Deutschlands--History--20th century--Congresses.
Socialism--Germany--20th century--Congresses.
Socialism--Germany--History--20th century--Congresses.
Sozialdemokratische Partei Deutschlands--History--20th century--Congresses.
Sozialistische Einheitspartei Deutschlands--History--Congresses.
Princeton subject headings:
Communism--Germany--History--20th century--Congresses.
Germany (East)--Politics and government--Congresses.
Kommunistische Partei Deutschlands--History--20th century--Congresses.
Socialism--Germany--History--20th century--Congresses.
Sozialdemokratische Partei Deutschlands--History--20th century--Congresses.
Sozialistische Einheitspartei Deutschlands--History--Congresses.