@book { ElectronicCommerceundR3,
    title = "Electronic Commerce und R/3",
    author = "Nick {Melekian}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832449223",
    url = "https://m.diplom.de/document/220489"
}