https://cel.archives-ouvertes.fr/cel-00376447 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Friday, April 17, 2009 - 3:14:17 PM Last modification on : Sunday, June 26, 2022 - 5:27:01 AM Long-term archiving on: : Thursday, June 10, 2010 - 6:16:52 PM