Columbia subject headings:
Harvard subject headings:
Europe, Central--Commerce--Russia (Federation)
Europe, Eastern--Commerce--Russia (Federation)
Gas industry--Russia (Federation)
Natural gas--Russia (Federation)
Russia (Federation)--Commerce--Europe, Central.
Russia (Federation)--Commerce--Europe, Eastern.
Princeton subject headings:
Europe--Commerce--Russia (Federation).
Gas industry--Russia (Federation)
Russia (Federation)--Commerce--Europe.