https://hal-upec-upem.archives-ouvertes.fr/hal-00628163 Contributor : Marie-Pierre BéalConnect in order to contact the contributor Submitted on : Friday, September 30, 2011 - 3:19:52 PM Last modification on : Saturday, January 15, 2022 - 3:56:47 AM Long-term archiving on: : Saturday, December 31, 2011 - 2:40:12 AM