Columbia subject headings:
Harvard subject headings:
Communist party purges--History--20th century.
Soviet Union--Politics and government--1936-1953.
Soviet Union. Narodnyĭ komissariat vnutrennikh del
Stalin, Joseph, 1878-1953
Princeton subject headings:
Political persecution--Soviet Union--History--20th century.
Political purges--Soviet Union--History--20th century.
Soviet Union--Politics and government--1936-1953.