Affiliation: | 1. Department of Mathematics, Eastern University, Chenkalady, Sri Lanka;2. School of Mathematics, University of the Witwatersrand, P O Wits 2050, Johannesburg, South Africa;3. Centre for Differential Equations, Continuum Mechanics and Applications, University of the Witwatersrand, P O Wits 2050, Johannesburg, South Africa;4. School of Computational and Applied Mathematics, University of the Witwatersrand, P O Wits 2050, Johannesburg, South Africa |