@book { KernkompetenzenvonprofessionellenFuballklubs,
    title = "Kernkompetenzen von professionellen Fußballklubs",
    author = "Jochen {Schreiber}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836609746",
    url = "https://m.diplom.de/document/225593"
}