Author/Authors :
Taghavi Ali نويسنده Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran. , Alizadeh Afrouzi Ghasem نويسنده Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran. , Ghorbani Horieh نويسنده Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran.