@book { CustomerRelationshipManagementZieleElementeundAusgestaltung,
    title = "Customer Relationship Management. Ziele, Elemente und Ausgestaltung",
    author = "Judith {Mittmann}",
    year = "2014",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    url = "https://www.hausarbeiten.de/document/279966"
}