@book { MarktanalysedesOutdoorMarktesamPointofSaledesSporthandels,
    title = "Marktanalyse des Outdoor-Marktes am Point of Sale des Sporthandels",
    author = "Bernd {Polotzek}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836627023",
    url = "https://m.diplom.de/document/226622"
}