@book { CustomerRelationshipManagementCRMberblickbereinneuesParadigmadesMarketings,
    title = "Customer Relationship Management (CRM). Überblick über ein neues Paradigma des Marketings",
    author = "Christopher {Holfeld}",
    year = "2015",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    url = "https://www.hausarbeiten.de/document/288685"
}