@book { RohstoffeundRohstoffderivateinderPortfoliotheorie,
    title = "Rohstoffe und Rohstoffderivate in der Portfoliotheorie",
    author = "Christoph {Lang}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836643832",
    url = "https://m.diplom.de/document/227656"
}