Columbia subject headings:
Germany--Politics and government--1918-1933.
Sozialdemokratische Partei Deutschlands--History.
Harvard subject headings:
Germany--Politics and government--1918-1933
Socialism--Germany--History
Sozialdemokratische Partei Deutschlands--History--20th century.
Princeton subject headings:
Germany--Politics and government--1918-1933.
Sozialdemokratische Partei Deutschlands--History--20th century.