Columbia subject headings:
Political purges--Soviet Union--History.
Soviet Union--Politics and government--1917-1936.
Soviet Union--Politics and government--1936-1953.
Trials--Soviet Union.
Harvard subject headings:
Political purges--Soviet Union--History.
Soviet Union--Politics and government--1917-1936.
Soviet Union--Politics and government--1936-1953.
Trials--Soviet Union.
Princeton subject headings:
Soviet Union--Politics and government--1917-1936.