@book { KritischeLebensereignisseBelastungoderHerausforderung,
    title = "Kritische Lebensereignisse: Belastung oder Herausforderung?",
    author = "Ann-Kathrin {Christiansen}",
    year = "2015",
    publisher = "BACHELOR + MASTER PUBLISHING",
    address = "Hamburg, Deutschland",
    url = "https://m.bachelor-master-publishing.de/document/297823"
}