Columbia subject headings:
Agricultural machinery--Russia (Federation)--Central Chernozem Region.
Agricultural machinery--Soviet Union.
Agriculture and state--Soviet Union.
Central Chernozem Region (Russia)--Rural conditions--20th century.
Machine-tractor stations--Russia (Federation)--Central Chernozem Region.
Harvard subject headings:
Agricultural machinery--Russia (Federation)--Central Chernozem Region.
Agriculture and state--Soviet Union.
Machine-tractor stations--Russia (Federation)--Central Chernozem Region.
Princeton subject headings: