@book { KundenzufriedenheitsanalyseimFuball,
    title = "Kundenzufriedenheitsanalyse im Fußball",
    author = "André {Bregler}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832446185",
    url = "https://m.diplom.de/document/220232"
}