Evelyne Hubert Notes on Triangular Sets and Triangulation-Decomposition Algorithms II: Differential Systems. 40-87 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2630&spage=40 2001 conf/snsc/2001 SNSC db/conf/snsc/snsc2001.html#Hubert01a