@book { NachhaltigeEntwicklungeineLeitidee,
    title = "Nachhaltige Entwicklung - eine Leitidee",
    author = "Anja {Pöche}",
    year = "2008",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638032858",
    url = "https://www.hausarbeiten.de/document/87528"
}