@book { IntegrationandDisIntegrationandtheNaturalGasMarketinpostSovietCountries19892001,
    title = "Integration and Dis-Integration and the Natural Gas Market in post-Soviet Countries 1989-2001",
    author = "Sven {Grählert}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832494827",
    url = "https://m.diplom.de/document/224613"
}