@book { StrategischeKooperationenimProfifuball, title = "Strategische Kooperationen im Profifußball", author = "Andreas {Wehlitz}", year = "2005", publisher = "Diplom.de", address = "Hamburg, Deutschland", doi = "10.3239/9783832485481", url = "https://m.diplom.de/document/223748" }