http://hal.in2p3.fr/in2p3-00021771 Contributor : Claudine BombarConnect in order to contact the contributor Submitted on : Monday, May 10, 2004 - 3:39:38 PM Last modification on : Friday, January 22, 2021 - 10:02:03 AM Long-term archiving on: : Wednesday, March 31, 2010 - 2:07:19 PM