Luis Álvarez Carmelo Cuenca Javier Sánchez Regularization of 3D Cylindrical Surfaces. 37-44 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2652&spage=37 2003 conf/ibpria/2003 IbPRIA db/conf/ibpria/ibpria2003.html#AlvarezCS03