https://cel.archives-ouvertes.fr/cel-00392218 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Friday, June 5, 2009 - 5:15:36 PM Last modification on : Tuesday, December 7, 2021 - 4:04:33 PM Long-term archiving on: : Thursday, June 30, 2011 - 10:52:22 AM