https://hal.archives-ouvertes.fr/hal-02006606 Contributor : Mioara JoldesConnect in order to contact the contributor Submitted on : Monday, February 4, 2019 - 4:53:19 PM Last modification on : Monday, July 4, 2022 - 9:02:02 AM Long-term archiving on: : Sunday, May 5, 2019 - 4:30:25 PM