@book { UnternehmensbewertungKennzahlenanalyse,
    title = "Unternehmensbewertung & Kennzahlenanalyse",
    author = "Nicolas {Schmidlin}",
    year = "2020",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1193866"
}