@book { KundenbindungeinerZahnarztpraxis,
    title = "Kundenbindung einer Zahnarztpraxis",
    author = "Anne {Wittig}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640846887",
    url = "https://www.hausarbeiten.de/document/167722"
}