Columbia subject headings:
Feudalism--Soviet Union--Historiography.
Grekov, B. D. (Boris Dmitrievich), 1882-1953.
Historians--Soviet Union.
Soviet Union--History.
Harvard subject headings:
Feudalism--Europe, Eastern--Historiography.
Feudalism--Historiography
Feudalism--History.
Grekov, B. D. (Boris Dmitrievich), 1882-1953
Russia--History--To 1533.
Princeton subject headings:
Feudalism--Historiography.
Feudalism--History.
Grekov, B. D. (Boris Dmitrievich), 1882-1953.