| Affiliation: | 1. School of Science and Technology, Cape Breton University, Sydney, Nova Scotia, B1P 6L2, Canada;2. School of Mathematics and Statistics, Northeast Normal University, Changchun, 130024, PR China;3. Department of Mathematics, Champlain College St.-Lambert, St.-Lambert, Quebec, J4P 3P2, Canada;4. Department of Mathematics and Statistics, McGill University, Montreal, Quebec, H3A 2K6A, Canada;1. College of Mathematics, Faculty of Science, Beijing University of Technology, Beijing 100022, China;2. College of Sciences, Beijing Information Science and Technology University, Beijing 100192, China;3. Department of Mathematics, Champlain College Saint-Lambert, Quebec, J4P 3P2, Canada;4. Department of Mathematics and Statistics, McGill University, Montreal, Quebec, H3A 2K6, Canada |
