https://cel.archives-ouvertes.fr/cel-00392164 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Friday, June 5, 2009 - 4:11:42 PM Last modification on : Saturday, January 15, 2022 - 4:09:00 AM Long-term archiving on: : Thursday, June 10, 2010 - 10:15:51 PM