GARDING, Lars. Dirichlet’s problem for linear elliptic partial differential equations. Mathematica Scandinavica, Berkeley, CA, United States, v. 1, p. 55–72, 1953. DOI: 10.7146/math.scand.a-10364. Disponível em: https://journals.msp.org/mscand/article/view/2957. Acesso em: 25 jul. 2026.