@book { DerOnlineLieferservicefrLebensmittel,
    title = "Der Online-Lieferservice für Lebensmittel",
    author = "Bärbel {Rücker}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832429737",
    url = "https://m.diplom.de/document/218696"
}