https://cel.archives-ouvertes.fr/cel-00092968 Contributor : Administrateur de CelConnect in order to contact the contributor Submitted on : Tuesday, September 12, 2006 - 3:27:54 PM Last modification on : Wednesday, September 12, 2018 - 2:14:02 PM Long-term archiving on: : Monday, April 5, 2010 - 10:37:38 PM