@book { EinsatzfelderfrCustomerRelationshipManagementSoftware,
    title = "Einsatzfelder für Customer-Relationship-Management-Software",
    author = "Andreas {Hoffmann}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640950676",
    url = "https://www.hausarbeiten.de/document/174390"
}