@book { CorporateSocialResponsibilityimdeutschenProfifuball,
    title = "Corporate Social Responsibility im deutschen Profifußball",
    author = "Levin {de Haen}",
    year = "2012",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656137290",
    url = "https://www.hausarbeiten.de/document/189496"
}