Cristiana Bolchini Giorgio Orsi Elisa Quintarelli Fabio A. Schreiber Letizia Tanca Context Modeling and Context Awareness: steps forward in the Context-ADDICT project. 47-54 2011 34 IEEE Data Eng. Bull. 2 http://sites.computer.org/debull/A11june/Tanca.pdf db/journals/debu/debu34.html#BolchiniOQST11