https://cel.archives-ouvertes.fr/cel-00563376 Contributor : Jean-Luc ArchimbaudConnect in order to contact the contributor Submitted on : Friday, February 4, 2011 - 4:41:27 PM Last modification on : Thursday, January 11, 2018 - 6:19:34 AM Long-term archiving on: : Thursday, May 5, 2011 - 3:34:57 AM