@book { DeutschesSpracheschweresSprache,
    title = "Deutsches Sprache, schweres Sprache",
    author = "René {Zach}",
    year = "2010",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640698653",
    url = "https://www.hausarbeiten.de/document/157426"
}