@book { ElectronicProcurementaufvirtuellenMarktpltzen,
    title = "Electronic Procurement auf virtuellen Marktplätzen",
    author = "Matthias {Knoch}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832426910",
    url = "https://m.diplom.de/document/218433"
}