@book { ValueatRisk,
    title = "Value at Risk",
    subtitle = "Analytische Ansätze zur Messung von Marktpreisrisiken",
    author = "Christoph A. {Butz}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832438326",
    url = "https://m.diplom.de/document/219508"
}