@book { PersonalcontrollingBegriffeInstrumenteAufgabenbereiche,
    title = "Personalcontrolling. Begriffe, Instrumente, Aufgabenbereiche",
    author = "Sergej {Belsch}",
    year = "2014",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    url = "https://www.hausarbeiten.de/document/284880"
}