https://cel.archives-ouvertes.fr/cel-00648243 Contributor : Sylvie FloresConnect in order to contact the contributor Submitted on : Monday, December 5, 2011 - 2:09:44 PM Last modification on : Monday, October 15, 2018 - 3:54:02 PM Long-term archiving on: : Tuesday, March 6, 2012 - 2:32:12 AM