@book { FormenderHandelskommunikation,
    title = "Formen der Handelskommunikation",
    author = "Andrea {May}",
    year = "2003",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638213387",
    url = "https://www.hausarbeiten.de/document/16492"
}