@book { BasiswissenZivilesWirtschaftsrecht,
    title = "Basiswissen Ziviles Wirtschaftsrecht",
    author = "Knut Werner {Lange}",
    year = "2015",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220945"
}