@book { EntwicklungundStatusquodesVersandhandelsinDeutschland,
    title = "Entwicklung und Status quo des Versandhandels in Deutschland",
    author = "Britta {Heitmüller}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832409302",
    url = "https://m.diplom.de/document/216830"
}