@book { TheevolutionprocessoftheCloudComputingBusinessModel,
    title = "The evolution process of  the Cloud Computing Business Model",
    author = "Jan  {Morgenthal}",
    year = "2013",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656351658",
    url = "https://www.hausarbeiten.de/document/207878"
}