@book { SportsponsoringimBereichFuball,
    title = "Sportsponsoring im Bereich Fußball",
    author = "Frank {Schriegel}",
    year = "2004",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638261234",
    url = "https://www.hausarbeiten.de/document/22893"
}