@book { DerSchutzterritorialbeschrnkterKennzeichen,
    title = "Der Schutz territorial beschränkter Kennzeichen",
    author = "Jürgen {Fleckenstein}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1088682"
}