@book { DasdunkleHerzderVilla,
    title = "Das dunkle Herz der Villa",
    subtitle = "Roman",
    author = "Barbara {Michaels} and Hilde {Linnert}",
    year = "2020",
    publisher = "dotbooks Verlag",
    address = "München, Germany",
    url = "https://www.dotbooks.de/document/540185"
}