1. Nonlinear Analysis Group (NAG), Mathematics Department, Virtual University of Pakistan, Lahore, Pakistan
2. Institute for Groundwater Studies, University of the Free State, Bloemfontein, South Africa
3. Department of Automation, Biomechanics and Mechatronics, Lodz University of Technology, Lodz, Poland
4. Department of Mathematics, University of Management and Technology, Lahore, Pakistan