@book { DerMarktdesSpielwarenEinzelhandelsinNrnberg,
    title = "Der Markt des Spielwaren-Einzelhandels in Nürnberg",
    author = "Marco {Wagner}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832473532",
    url = "https://m.diplom.de/document/222644"
}