Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 38 4 2012 12 15 Fully idempotent and coidempotent modules987 1005 en Habibollah Ansari-Toroghy University of Guilan Faranak Farshadifar University of Guilan 2011 02 10 Idempotent submodule fully idempotent module coidempotent submodule copure submodule and fully coidempotent module