@book { FuhrparkoutsourcingChancenoderRisiken,
    title = "Fuhrparkoutsourcing - Chancen oder Risiken",
    author = "Thomas {Klann}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832410452",
    url = "https://m.diplom.de/document/216937"
}