Ivaylo Ilinkin Ravi Janardan Michiel H. M. Smid Eric Johnson Paul Castillo Jörg Schwerdt Heuristics for estimating contact area of supports in layered manufacturing. 2006 11 ACM Journal of Experimental Algorithmics http://doi.acm.org/10.1145/1187436.1210589 db/journals/jea/jea11.html#IlinkinJSJCS06