@book { QuovadisGewerkschaft,
    title = "Quo vadis, Gewerkschaft?",
    author = "Martin {Hille}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832478278",
    url = "https://m.diplom.de/document/223085"
}