@book { EingemeineuropischesKaufrecht,
    title = "Ein gemeineuropäisches Kaufrecht",
    subtitle = "Vision oder nahe Zukunft?",
    author = "Viola {Heutger}",
    year = "2007",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1103429"
}