@book { SozialpolitikineinerFderation,
    title = "Sozialpolitik in einer Föderation",
    subtitle = "Eine theoretische Analyse bei Mobilität",
    author = "Jörg {Hülshorst}",
    year = "2000",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1090172"
}