https://cel.archives-ouvertes.fr/cel-00281762 Contributor : Alain YgerConnect in order to contact the contributor Submitted on : Saturday, May 24, 2008 - 9:38:19 AM Last modification on : Saturday, December 4, 2021 - 3:42:21 AM Long-term archiving on: : Friday, September 28, 2012 - 2:56:24 PM