https://hal-ens-lyon.archives-ouvertes.fr/ensl-00391070 Contributor : Jean-Michel MullerConnect in order to contact the contributor Submitted on : Wednesday, June 3, 2009 - 1:10:14 PM Last modification on : Friday, February 4, 2022 - 3:15:58 AM Long-term archiving on: : Monday, October 15, 2012 - 11:41:22 AM