1. Department of Mathematics and Computer Science, University of Africa, Toru Orua, Bayelsa State, Nigeria
2. Department of Mathematics and Statistics, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria
3. Department of Community Medicine, Ladoke Akintola University of Technology Teaching Hospital, Ogbomosho, Nigeria
4. School of Computing, University of Eastern Finland, Kuopio, Finland