Columbia subject headings:
Soviet Union--History--Revolution, 1917-1921.
Harvard subject headings:
Russia--History--Nicholas II, 1894-1917.
Russia--Politics and government--1894-1917.
Soviet Union--History--Revolution, 1917-1921.
Soviet Union--Politics and government--1917-1936.
Princeton subject headings:
Soviet Union--History--Revolution, 1917-1921.