1. a International Institute for Symmetry Analysis and Mathematical Modeling, Department of Mathematical Sciences, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, Republic of South Africa
2. b International Institute for Symmetry Analysis and Mathematical Modeling, Department of Mathematical Sciences, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, Republic of South Africa; Center for Research and Education in Optical Seiences and Applications, Department of Applied Mathematics and Theoretical Physics, Delaware State University, Dover, DE 19901–2277, USA