@book { RohstoffealsInvestmentklasse,
    title = "Rohstoffe als Investmentklasse",
    author = "Markus L. {Huszar}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836610056",
    url = "https://m.diplom.de/document/225612"
}