@book { LigasponsoringimProfisport,
    title = "Ligasponsoring im Profisport",
    subtitle = "Unter besonderer Berücksichtigung des Profifußballs",
    author = "Christoph {Fischer}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832464998",
    url = "https://m.diplom.de/document/221916"
}