Salahuddin. “SYSTEM OF GENERALIZED HIERARCHICAL VARIATIONAL INEQUALITY PROBLEMS”. Journal of Nonlinear Analysis and Optimization: Theory & Applications (JNAO) 10, no. 2 (June 5, 2019): 69–82. accessed September 2, 2026. https://ph03.tci-thaijo.org/index.php/jnao/article/view/2845.