BROSAMLER, G. A. A probalistic solution of the Neumann problem. MATHEMATICA SCANDINAVICA, [S. l.], v. 38, p. 137–147, 1976. DOI: 10.7146/math.scand.a-11623. Disponível em: https://www.mscand.dk/article/view/11623. Acesso em: 3 may. 2024.