@book { HeadhuntingMglichkeitenundrechtlicheGrenzen,
    title = "Headhunting. Möglichkeiten und rechtliche Grenzen",
    author = "John {Penner}",
    year = "2013",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656463702",
    url = "https://www.hausarbeiten.de/document/230574"
}