Noelia Barreira Manuel G. Penedo Topological Active Volumes for Segmentation and Shape Reconstruction of Medical Images. 43-50 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3212&spage=43 2004 conf/iciar/2004-2 ICIAR (2) db/conf/iciar/iciar2004-2.html#BarreiraP04