Salvatore Orlando Renzo Orsini Alessandra Raffaetà Alessandro Roncato Claudio Silvestri Spatio-temporal Aggregations in Trajectory Data Warehouses. 66-77 2007 conf/dawak/2007 DaWaK http://dx.doi.org/10.1007/978-3-540-74553-2_7 db/conf/dawak/dawak2007.html#OrlandoORRS07