@book { NachhaltigeInvestments,
    title = "Nachhaltige Investments",
    subtitle = "Möglichkeiten und Probleme der Umsetzung",
    author = "Miriam {Unser}",
    year = "2014",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/272056"
}