@book { CustomerRelationshipManagementCRMundCRMSystemeVorschlgezurOptimierung, title = "Customer Relationship Management (CRM) und CRM-Systeme. Vorschläge zur Optimierung", author = "Nicolas {Teles}", year = "2007", publisher = "GRIN Verlag", address = "München, Germany", doi = "10.3239/9783638607902", url = "https://www.hausarbeiten.de/document/69871" }