1. Department of Mathematics and Applied Mathematics, University of Pretoria, Pretoria, South Africa
2. Department of Mathematics and Computer Sciences, University of Dschang, Dschang, Cameroon
3. African Peer Review Mechanism, Johannesburg, South Africa
4. Department of Mathematics Technology, Tshwane University of Technology, Pretoria, South Africa
5. Department of Mathematics and Applied Mathematics, University of Limpopo, Sovenga, South Africa