Columbia subject headings:
Internal security--Soviet Union.
Soviet Union. Ministerstvo vnutrennikh del--History.
Soviet Union. Narodnyĭ komissariat vnutrennikh del--History.
Harvard subject headings:
Internal security--Soviet Union
Soviet Union. Ministerstvo vnutrennikh del--History.
Soviet Union. Narodnyĭ komissariat vnutrennikh del--History.
Princeton subject headings:
Internal security--Soviet Union.