@book { DasCustomizingdesSAPR3HRModuls,
    title = "Das Customizing des SAP R/3 HR-Moduls",
    author = "Deniz {Akitürk}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832436803",
    url = "https://m.diplom.de/document/219367"
}