@inbook{hilty2015consolidation,
  title = {Consolidation, Colocation, Virtualization, and Cloud Computing: The Impact of the Changing Structure of Data Centers on Total Electricity Demand}
  author = {Hilty, Lorenz M. and Aebischer, Bernard and Hintemann, Ralph},
  url = {http://link.springer.com/10.1007/978-3-319-09228-7_7},
  year = {2015}
}