@book { SubstitutionvonReisebrosdurchdasInternet,
    title = "Substitution von Reisebüros durch das Internet?",
    author = "Sabine {Düx}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/218220"
}