Author/Authors :
M. A. Yaghoobi، M. A. Yaghoobi نويسنده Faculty of Mathematics and Computer Sciences, University of Kerman, Kerman, Iran M. A. Yaghoobi, M. A. Yaghoobi , M. Tamiz، M. Tamiz نويسنده Department of Mathematics, University of Portsmouth, Buckingham Building, Lion Terrace, Portsmouth, PO1 3HE, UK M. Tamiz, M. Tamiz