@book { ProjektarbeitimDaFUnterricht,
    title = "Projektarbeit im DaF-Unterricht",
    author = "Doreen {Frohwein}",
    year = "2007",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638619417",
    url = "https://www.hausarbeiten.de/document/71385"
}