Affiliation: | (1) Department of Mathematics, Ferdowsi University, P. O. Box 1159, Mashhad, 91775, Iran;(2) Centre of Excellence in Analysis on Algebraic Structures (CEAAS), Ferdowsi University, Ferdowsi, Iran;(3) Department of Mathematics, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece |