@book { StateoftheArtdesPersonalmarketings,
    title = "State of the Art des Personalmarketings",
    author = "Angelika {Kuchinka}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836610797",
    url = "https://m.diplom.de/document/225652"
}