@book { ImSchattendesPalio,
    title = "Im Schatten des Palio",
    subtitle = "Luca Marcettis erster Fall",
    author = "Kerstin {Groeper} and Guiseppe {Bruno}",
    year = "2017",
    publisher = "hey! publishing",
    address = "München, Germany",
    url = "https://www.heypublishing.com/document/373916"
}