Columbia subject headings:
Agriculture and state--Russia.
Agriculture and state--Soviet Union.
Crops and climate--Russia.
Crops and climate--Soviet Union.
Harvard subject headings:
Agriculture and state--Russia.
Agriculture and state--Soviet Union.
Crops and climate--Russia.
Crops and climate--Soviet Union.
Princeton subject headings:
Agriculture and state--Russia.
Agriculture and state--Soviet Union.
Crops and climate--Russia.
Crops and climate--Soviet Union.