Columbia subject headings:
Europe, Eastern--History.
Revolutions.
Soviet Union--History--Revolution, 1917-1921--Influence.
Harvard subject headings:
Europe, Eastern--Politics and government--1918-1945.
Europe, Eastern--Politics and government--1945-1989.
Soviet Union--History--Revolution, 1917-1921--Influence.
Princeton subject headings:
Europe, Eastern--Politics and government.
Soviet Union--History--Revolution, 1917-1921--Influence.