@book { OpportunitiesandDrawbacksofExtendedOpeningHoursversusOnlineShoppingintheGermanFoodTrade,
    title = "Opportunities and Drawbacks of Extended Opening Hours versus Online Shopping in the German Food Trade",
    author = "Martina {Schäfer}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832483609",
    url = "https://m.diplom.de/document/223552"
}