@book { QualittssicherungdurchWerbung,
    title = "Qualitätssicherung durch Werbung",
    author = "Andreas {Isbarn}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832482725",
    url = "https://m.diplom.de/document/223470"
}