TY - JOUR ID - 796 TI - Bulletin of the Iranian Mathematical Society JO - Bulletin of the Iranian Mathematical Society JA - BIMS LA - en SN - 1017-060X Y1 - 2016 PY - 2016 VL - 42 IS - 3 SP - EP - DO - N2 - UR - http://bims.iranjournals.ir/article_796.html L1 - http://bims.iranjournals.ir/article_796_dc33b7469948b4c04368c4273c896ac2.pdf ER -