@book { Morgensmittagsabends,
    title = "Morgens, mittags, abends",
    subtitle = "Ein Bilder-Buch für die Biografiearbeit",
    author = "Beate {Wolf} and Thomas {Haubold}",
    year = "2013",
    publisher = "Schlütersche Verlagsgesellschaft mbH & Co. KG",
    address = ", Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403828"
}