https://cel.archives-ouvertes.fr/cel-00168663 Contributor : Emmanuel MoulayConnect in order to contact the contributor Submitted on : Wednesday, August 29, 2007 - 3:40:41 PM Last modification on : Wednesday, April 27, 2022 - 3:49:36 AM Long-term archiving on: : Monday, September 24, 2012 - 11:55:15 AM