@book { BesteuerungderPersonenunternehmenab2008,
    title = "Besteuerung der Personenunternehmen ab 2008",
    author = "Timo {Kopmann}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836618847",
    url = "https://m.diplom.de/document/226114"
}