@book { KundenserviceimLebensmitteleinzelhandel,
    title = "Kundenservice im Lebensmitteleinzelhandel",
    author = "Oliver {Distel}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832411961",
    url = "https://m.diplom.de/document/217116"
}