Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 38 1 2012 04 01 Topological centers of the n-th dual of module actions1 16 en K. Haghnejad Azar University of Mohghegh Ardabili A. Riazi Amirkabir University of Technology 2010 01 26 Arens regularity bilinear mapping topological center