https://hal-univ-paris.archives-ouvertes.fr/hal-00707460 Contributor : Stéphanie BoulardConnect in order to contact the contributor Submitted on : Tuesday, June 12, 2012 - 4:30:35 PM Last modification on : Saturday, June 25, 2022 - 8:52:13 PM Long-term archiving on: : Thursday, September 13, 2012 - 2:35:09 AM