@book { OnlineGamesalsMarketingTool,
    title = "Online-Games als Marketing Tool",
    author = "Thomas {Blatt}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832489175",
    url = "https://m.diplom.de/document/224092"
}