@book { AreCustomersloyaltotheTescoSuperstoreinRoundhay,
    title = "Are Customers loyal to the Tesco Superstore in Roundhay",
    author = "Christina {Rüther}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832472054",
    url = "https://m.diplom.de/document/222509"
}