@book { FitundschlankdurchFitnesstraining,
    title = "Fit und schlank durch Fitnesstraining?!",
    author = "Vanessa {Paetke}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/222469"
}