https://hal-sfo.ccsd.cnrs.fr/sfo-00270686 Contributor : Joëlle SurrelConnect in order to contact the contributor Submitted on : Tuesday, April 22, 2008 - 7:57:26 PM Last modification on : Tuesday, January 16, 2018 - 3:00:01 PM Long-term archiving on: : Friday, May 21, 2010 - 1:24:15 AM