| Affiliation: | 1. Department of Mathematical Sciences, University of Memphis, Memphis TN 38152, United States;2. Mathematics Department, Dawson-Loeffler Science & Mathematics Bldg, Oklahoma City University, 2501 N. Blackwelder, Oklahoma City, OK 73106-1493, United States;1. Department of Mathematics, Macquarie University, NSW 2109, Australia;2. Dipartimento di Matematica, Sapienza – Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy;3. Mathematics Learning Centre, University of Sydney, NSW 2006, Australia |
