We present a Systematic Literature Review (SLR) on Cloud Computing that selected 39 papers from first tier journals and conferences in the period 2008-2012. The selective approach captures the relevant points of view on Cloud Computing, namely the overall paradigm in terms of delivery and deployment. Afterwards, we point out the technological issues about networking and data management in Cloud Computing. This SLR extends previous reviews thanks to a longer time period and a wider research sample.