@book { BeobachtungvonTierenamBeispielvonSchmetterlingen,
    title = "Beobachtung von Tieren, am Beispiel von Schmetterlingen",
    author = "Fatima {Oturak-Pieknik}",
    year = "2002",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638122665",
    url = "https://www.hausarbeiten.de/document/3668"
}