Columbia subject headings:
Germany--History--1918-1933.
Poland--History--1918-1945.
Revolutions and socialism.
Soviet Union--History--Revolution, 1917-1921.
Turkey--History--1918-1960.
Harvard subject headings:
Germany--History--1918-1933
Poland--History--1918-1945
Revolutions and socialism
Soviet Union--History--Revolution, 1917-1921
Turkey--History--1918-1960
Princeton subject headings:
Germany--History--1918-1933.
Poland--History--1918-1945.
Revolutions and socialism.
Soviet Union--History--Revolution, 1917-1921.
Turkey--History--1918-1960.