Ourraoui A. AN EXISTENCE RESULT FOR AN ELLIPTIC PROBLEM INVOLVING A FOURTH ORDER OPERATOR. J. Nonlinear Anal. Optim. [internet]. 2018 Jan. 19 [cited 2026 Sep. 2];7(2):51-6. available from: https://ph03.tci-thaijo.org/index.php/jnao/article/view/2831