@book { EmployeeStockOptionsinGermany,
    title = "Employee Stock Options in Germany",
    subtitle = "An exploratory study of employees’ perceptions on their use and effectiveness",
    author = "Nadia {Dirks}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832472986",
    url = "https://m.diplom.de/document/222596"
}