1. Damghan University, School of Mathematics and Computer science, Damghan, Iran + School of Mathematics, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
2. Ferdowsi University of Mashhad, Department of mathematics and center of excellence in analysis on algebraic structures, Iran
3. Ferdowsi University of Mashhad, Faculty of mathematical sciences, Department of pure Mathematics, Iran
4. Hakim Sabzevari University, Department of pure mathematics, Sabzevar, Iran