@book { WerkontrolliertdieTelefonberwachung,
    title = "Wer kontrolliert die Telefonüberwachung?",
    author = "Otto {Backes} and Christoph {Gusy}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1096070"
}