@book { RohstoffealsAssetklasse,
    title = "Rohstoffe als Assetklasse",
    author = "Andreas {Laubenthal}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836618960",
    url = "https://m.diplom.de/document/226121"
}