@book { DasHrspielderfnfzigerJahre,
    title = "Das Hörspiel der fünfziger Jahre",
    subtitle = "«Regionalliga Süd» und «Championsleague»",
    author = "Bettina {Hasselbring} and Renate {Ulm} and Susanne {Weichselbaumer}",
    year = "2007",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1102888"
}