@book { MehrsprachigkeitinderEuropischenUnion,
    title = "Mehrsprachigkeit in der Europäischen Union",
    author = "Jakob {Haselhuber}",
    year = "2013",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-02974-1",
    url = "https://www.peterlang.com/document/1047304"
}