@book { KundendienstManagement,
    title = "Kundendienst-Management",
    author = "H. {Meffert}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13623",
    url = "https://www.peterlang.com/document/1068218"
}