@book { SozialraumEuropa,
    title = "Sozialraum Europa",
    author = "Helmut {Böhme} and Alois {Peressin}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13657",
    url = "https://www.peterlang.com/document/1068249"
}