@book { DiegrauenWchterOperationNautilusAchterRoman,
    title = "Die grauen Wächter: Operation Nautilus - Achter Roman",
    author = "Wolfgang {Hohlbein}",
    year = "2018",
    publisher = "jumpbooks",
    address = "München, Deutschland",
    url = "https://m.jumpbooks.de/document/438037"
}