@book { PortfolioOptimierungvonKulturereignissen,
    title = "Portfolio-Optimierung von Kulturereignissen",
    author = "Nikolai {von Wurzbach}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832452421",
    url = "https://m.diplom.de/document/220767"
}