@book { SelbsthilfeperInternet,
    title = "Selbsthilfe per Internet",
    author = "Helen {Hertzsch}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832492373",
    url = "https://m.diplom.de/document/224360"
}