@book { DerInternationaleArbeitskampfnachArt9RomIIVerordnung,
    title = "Der Internationale Arbeitskampf nach Art. 9 Rom II-Verordnung",
    author = "Anja {Zelfel}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1107749"
}