https://cel.archives-ouvertes.fr/cel-00374419 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Wednesday, April 8, 2009 - 4:20:40 PM Last modification on : Tuesday, October 19, 2021 - 10:59:14 PM Long-term archiving on: : Thursday, June 10, 2010 - 8:05:23 PM