db/conf/gis/MaheshwariMS97.html Anil Maheshwari Pat Morin Jörg-Rüdiger Sack Progressive TINs: Algorithms and Applications. 24-29 GIS1997/P024.pdf 1997 conf/gis/97 ACM-GIS http://doi.acm.org/10.1145/267825.267834 db/conf/gis/gis97.html#MaheshwariMS97