https://cel.archives-ouvertes.fr/cel-00391793 Contributor : Cimpa CimpaConnect in order to contact the contributor Submitted on : Thursday, June 4, 2009 - 5:04:17 PM Last modification on : Tuesday, October 19, 2021 - 12:55:34 PM Long-term archiving on: : Thursday, June 10, 2010 - 10:12:49 PM