José Antônio Fernandes de Macêdo Christelle Vangenot Walied Othman Nikos Pelekis Elias Frentzos Bart Kuijpers Irene Ntoutsi Stefano Spaccapietra Yannis Theodoridis Trajectory Data Models. 123-150 2008 Mobility, Data Mining and Privacy http://dx.doi.org/10.1007/978-3-540-75177-9_6 series/springer/2008mdmp db/series/springer/mdmp2008.html#MacedoVOPFKNST08