@book { PreispolitikimInternet,
    title = "Preispolitik im Internet",
    author = "Carsten {Herzog}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832448042",
    url = "https://m.diplom.de/document/220163"
}