Emanuele Danovaro Leila De Floriani Paola Magillo Mohammed Mostefa Mesmoudi Enrico Puppo Morphology-driven simplification and multiresolution modeling of terrains. 63-70 2003 conf/gis/2003 GIS http://doi.acm.org/10.1145/956676.956685 db/conf/gis/gis2003.html#DanovaroFMMP03