@book { TheIBMModelofElectronicCustomerRelationshipManagement,
    title = "The IBM Model of Electronic Customer Relationship Management",
    author = "Christian {Uwagwuna}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640896653",
    url = "https://www.hausarbeiten.de/document/170555"
}