G. Mayelvaganan, and S. Sekar. “A Quadratic Functional Equation Stability in 2-Banach Spaces”. Malaya Journal of Matematik 8, no. 04 (October 1, 2020): 2045–2049. Accessed November 22, 2024. https://www.malayajournal.org/index.php/mjm/article/view/1840.