@book { StockOptionPlnefrFhrungskrfte,
    title = "Stock Option Pläne für Führungskräfte",
    author = "Inna {Luft}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832498177",
    url = "https://m.diplom.de/document/224934"
}