[1] Université de technologie de Compiègne,LMAC (Laboratory of Applied Mathematics of Compiègne)
[2] King Khalid University,Department of Mathematics, College of Science
[3] Université Djillali Liabès,undefined
[4] L.S.P.S.,undefined
[5] Université Abdelhamid Ibn Badis de Mostaganem,undefined