@book { VielsprachigesEuropa,
    title = "Vielsprachiges Europa",
    author = "Eva {Gugenberger} and Mechthild {Blumberg}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1095158"
}