Pr. El Amir Djeffal
Mathematics Department
Faculty of Mathematics and computer science
University of Batna 2, Batna
Algeria
E-mail: l.djeffal@univ-batna2.dz
Web: http://staff.univ-batna2.dz/djeffal-el-amir
Tel: 00213 667 659 689
Pr. DJEFFAL El Amir
Département de Mathématiques
Université de Batna 2, Batna, Algérie
