1. N. Hosseinioun:
Department of Statistics, School of Mathematical Sciences, Ferdowsi University of Mashhad, Iran
2. H. Doosti:
Department of Statistics, School of Mathematical Sciences, Ferdowsi University of Mashhad, Iran
3. H. A. Niroumand:
Department of Statistics, School of Mathematical Sciences, Ferdowsi University of Mashhad, Iran