@book { ArbeitsrechtlicheProblemebeimOutsourcing,
    title = "Arbeitsrechtliche Probleme beim Outsourcing",
    author = "Björn {Walter}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832419394",
    url = "https://m.diplom.de/document/217783"
}