BAERNSTEIN II, A.; V. KOVALEV, L. On Hölder regularity for elliptic equations of non-divergence type in the plane. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, [S. l.], v. 4, n. 2, p. 295-317, 2009. DOI: 10.2422/2036-2145.2005.2.04. Disponível em: http://20.103.181.36/index.php/annaliscienze/article/view/69. Acesso em: 28 may. 2025.