@book { DasBeurteilungssystemderBielefelderLaborschule,
    title = "Das Beurteilungssystem der Bielefelder Laborschule",
    author = "Sophie {Männel}",
    year = "2008",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640221189",
    url = "https://www.hausarbeiten.de/document/118772"
}