@book { DerSchmetterlingsmrder,
    title = "Der Schmetterlingsmörder",
    subtitle = "Psychothriller",
    author = "Guido M. {Breuer}",
    year = "2015",
    publisher = "dotbooks Verlag",
    address = "München, Deutschland",
    url = "https://www.dotbooks.de/document/309458"
}