Affiliation: | 1. Department of Mathematics, Ferdowsi University of Mashhad, Vakil Abad Blvd., Mashhad 91775-1159, Iran;2. Department of Business Administration, Royal Military College of Canada, Kingston, ON, Canada K7K7B4;3. M.G.DeGroote School of Business, McMaster University, Hamilton, ON, Canada L8S4M4 |