http://hal.in2p3.fr/in2p3-00019291 Contributor : Suzanne RobertConnect in order to contact the contributor Submitted on : Tuesday, April 24, 2001 - 11:11:22 AM Last modification on : Wednesday, September 16, 2020 - 4:06:48 PM Long-term archiving on: : Friday, February 11, 2011 - 4:22:15 PM