@book { UnterrichtsstundeBiologieDieZellealsoffenesSystem,
    title = "Unterrichtsstunde Biologie - Die Zelle als offenes System",
    author = "Sebastian  {Schopp}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640809622",
    url = "https://www.hausarbeiten.de/document/165334"
}