webpage http://www.scopus.com/inward/record.url?eid=2-s2.0-84862670363&partnerID=MN8TOARS http://dx.doi.org/10.1145/2213836.2213941
published in Proceedings of the 2012 ACM SIGMOD International Conference on Management of Data Journal Proceedings of the 2012 ACM SIGMOD International Conference on Management of Data Proceedings Proceedings of the ACM SIGMOD International Conference on Management of Data Proceedings