@book { MultiprojektmanagementimPublicSector,
    title = "Multiprojektmanagement im Public Sector",
    author = "Carsten {Ulferts}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836628273",
    url = "https://m.diplom.de/document/226713"
}