@book { GeschichtederErwachsenenbildung,
    title = "Geschichte der Erwachsenenbildung",
    author = "Madeleine {Nickel}",
    year = "2005",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638382878",
    url = "https://www.hausarbeiten.de/document/39550"
}