@book { Besserkonzentrieren,
    title = "Besser konzentrieren",
    subtitle = "Der Workshop für ein besseres Gedächtnis. Konzentration in allen Lebenslagen",
    author = "Carola {Wegerle}",
    year = "2011",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403323"
}