https://cel.archives-ouvertes.fr/cel-00281761 Contributor : Alain YgerConnect in order to contact the contributor Submitted on : Saturday, May 24, 2008 - 9:30:52 AM Last modification on : Saturday, December 4, 2021 - 3:42:21 AM Long-term archiving on: : Friday, November 25, 2016 - 10:41:02 PM