@book { DieKreuzfahrt,
    title = "Die Kreuzfahrt",
    subtitle = "Ein kulturelles Ereignis",
    author = "Annette {Schneider} and Uta {Steinmetz}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832446833",
    url = "https://m.diplom.de/document/220289"
}