José Silvestre Silva Beatriz Sousa Santos Augusto Silva Joaquim Madeira A Level-Set Based Volumetric CT Segmentation Technique: A Case Study with Pulmonary Air Bubbles. 68-75 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3212&spage=68 2004 conf/iciar/2004-2 ICIAR (2) db/conf/iciar/iciar2004-2.html#SilvaSSM04