@book { ArbeitsmotivationltererMitarbeiter,
    title = "Arbeitsmotivation älterer Mitarbeiter",
    author = "Thomas {Dittrich}",
    year = "2012",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656292180",
    url = "https://www.hausarbeiten.de/document/201064"
}