@book { BusinessplanMobilligGmbH,
    title = "Businessplan Mobillig GmbH",
    author = "Marcel {Daum}",
    year = "2006",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638493543",
    url = "https://www.hausarbeiten.de/document/54076"
}