Gian Paolo Lorenzetto Amitava Datta A Linear Time Heuristics for Trapezoidation of GIS Polygons. 75-84 2002 conf/iccS/2002-3 International Conference on Computational Science (3) http://link.springer.de/link/service/series/0558/bibs/2331/23310075.htm db/conf/iccS/iccS2002-3.html#LorenzettoD02