1. School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban 4041, South Africa
2. Department of Mathematics, University of Calabar, Calabar 540271, Nigeria
3. Department of Mathematics, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
4. Department of Basic Engineering, Faculty of Engineering, Menoufia University, Shibin el Kom 32511, Egypt
5. Department of Mathematics, University of Eswatini, Kwaluseni M201, Eswatini
6. Department of Mathematics and Applied Mathematics, Sefako Makgatho Health Sciences University, P.O. Box 94, Pretoria 0204, South Africa