@book { InstrumentezurMotivationvonAuendienstmitarbeitern,
    title = "Instrumente zur Motivation von Außendienstmitarbeitern",
    author = "Michael {Kaube}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832403874",
    url = "https://m.diplom.de/document/216365"
}