@book { ErfolgsfaktorenvonCustomerRelationshipManagementCRMStrategieninUnternehmen,
    title = "Erfolgsfaktoren von  Customer Relationship Management (CRM) Strategien in Unternehmen",
    author = "Klaus {Sevenich}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836647762",
    url = "https://m.diplom.de/document/227823"
}