https://cel.archives-ouvertes.fr/cel-00365584 Contributor : Mathias LegrandConnect in order to contact the contributor Submitted on : Tuesday, March 3, 2009 - 6:00:37 PM Last modification on : Thursday, June 18, 2020 - 12:32:04 PM Long-term archiving on: : Friday, October 12, 2012 - 12:45:51 PM