@book { NachgefragtdieSystemtheorieimPraxistest,
    title = "Nachgefragt - die Systemtheorie im Praxistest",
    author = "Simone {Becker}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836611770",
    url = "https://m.diplom.de/document/225710"
}