https://cel.archives-ouvertes.fr/cel-00660507 Contributor : Badr BenmammarConnect in order to contact the contributor Submitted on : Monday, January 16, 2012 - 8:48:24 PM Last modification on : Monday, December 20, 2021 - 4:50:11 PM Long-term archiving on: : Tuesday, April 17, 2012 - 2:45:07 AM