@book { DerdemographischeWandelinSchleswigHolstein,
    title = "Der demographische Wandel in Schleswig-Holstein",
    author = "Stefanie {Dreyer}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832498740",
    url = "https://m.diplom.de/document/224991"
}