Nguen, Byong. “Convergence Rates and Finite-Dimensional Approximation for a Class of Ill-Posed Variational Inequalities”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 5 (May 25, 1997): 629–637. Accessed May 18, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5043.