ADOLFSSON, Vilhelm. $L^2$-Integrability of Second Order Derivatives for Poisson’s Equation in Nonsmooth Domains. Mathematica Scandinavica, Berkeley, CA, United States, v. 70, p. 146–160, 1992. DOI: 10.7146/math.scand.a-12391. Disponível em: https://journals.msp.org/mscand/article/view/1259. Acesso em: 24 jul. 2026.