@book { Web20,
    title = "Web 2.0",
    subtitle = "Auswirkungen auf internetbasierte Geschäftsmodelle",
    author = "Christian {Kuhn}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836617314",
    url = "https://m.diplom.de/document/226035"
}