Columbia subject headings:
Political persecution--Soviet Union.
Soviet Union--History--1917-1936.
Harvard subject headings:
Political atrocities--Soviet Union.
Political persecution--Soviet Union.
Soviet Union--History--1917-1936.
Soviet Union--History--1939-1945.
Soviet Union--History--Revolution, 1917-1921--Atrocities.
Princeton subject headings:
Political atrocities--Soviet Union.
Political persecution--Soviet Union.
Soviet Union--History--1917-1936.
Soviet Union--History--1939-1945.
Soviet Union--History--Revolution, 1917-1921--Atrocities.