https://cel.archives-ouvertes.fr/cel-00392212 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Friday, June 5, 2009 - 5:02:47 PM Last modification on : Wednesday, December 9, 2020 - 3:10:44 PM Long-term archiving on: : Monday, October 15, 2012 - 11:56:16 AM