A GENERALIZATION OF THE STABILITY OF A QUARTIC FUNCTIONAL EQUATION IN QUASI-β-NORMED SPACES WITH THE FIXED POINT METHOD. Journal of Mathematical Analysis, [S. l.], v. 17, n. 01, p. 68–85, 2026. DOI: 10.5281/9sdkzd34. Disponível em: https://scopushub.com/index.php/JMA/article/view/26. Acesso em: 4 aug. 2026.