JOHN M. RASSIAS; M. ARUNKUMAR; S. RAMAMOORTHI; S. HEMALATHA. Ulam - Hyers stability of a 2- variable AC - mixed type functional equation in quasi - beta normed spaces: direct and fixed point methods. Malaya Journal of Matematik, India, v. 2, n. 02, p. 108–128, 2014. DOI: 10.26637/mjm202/003. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/397. Acesso em: 5 nov. 2024.