@book { DieMglichkeitendesITOutsourcing,
    title = "Die Möglichkeiten des IT-Outsourcing",
    author = "Argun {Aytuna}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832439927",
    url = "https://m.diplom.de/document/219629"
}