Nguyen, Thi Thanh Ly. “The Ulam-Hyers Stability of 2-Variable Radical Functional Equations in Quasi-Banach Spaces”. Dong Thap University Journal of Science - Natural Sciences Issue 13, no. 5 (June 26, 2024): 64–68. Accessed November 10, 2026. https://dthujs.vn/index.php/nsen/article/view/1488.