@book { DerRaumderFreiheitderSicherheitunddesRechts,
    title = "Der Raum der Freiheit, der Sicherheit und des Rechts",
    author = "Valeska {Nieden}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b14788",
    url = "https://www.peterlang.com/document/1057212"
}