publication Journal Article • R. Butt: Shape problems and Nonlinear Variational Inequalities, 26092 (Accepted) Int. Journal of Development Research, (2023). more of publication The approximation of fourth-order nonlinear variational inequalities, J. Eng App Sci Technol, 2023. by Rizwan Butt 2023 • R. Butt: Shape problems and Nonlinear Variational Inequalities, 26092 (Accepted) Int. Journal of Development Research, (2023). • Saleem Obaidat and Rizwan Butt; A new implicit symmetric method of sixth algebraic order with vanished phase-lag and its first derivative for solving Schrödinger's equation, Open Mathematics ISI Journal, 2021; 19: 225–237