Authors
Khedidja Bey
Laboratoire de Mathmatiques Pures et Appliques, University of Laghouat 03000, Laghouat, Algeria
Amar Belacel
Laboratoire de Mathmatiques Pures et Appliques, University of Laghouat 03000, Laghouat, Algeria
© 2021 Khedidja Bey, Amar Belacel, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.