Natalia V. Andrienko Gennady L. Andrienko Nikos Pelekis Stefano Spaccapietra 15-38 2008 Mobility, Data Mining and Privacy http://dx.doi.org/10.1007/978-3-540-75177-9_2 series/springer/2008mdmp db/series/springer/mdmp2008.html#AndrienkoAPS08