@book { WohnstandortInnenstadt,
    title = "Wohnstandort Innenstadt",
    subtitle = "Das Beispiel Mülheim an der Ruhr",
    author = "Tanja {Linken}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832497910",
    url = "https://m.diplom.de/document/224908"
}