FUGLEDE, B. The Symmetric Normal Derivative of a Subharmonic Function II. MATHEMATICA SCANDINAVICA, [S. l.], v. 12, p. 129–146, 1963. DOI: 10.7146/math.scand.a-10677. Disponível em: https://www.mscand.dk/article/view/10677. Acesso em: 25 apr. 2024.