GARDINER, S. J. Maximum principles for subharmonic functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 68, p. 210–220, 1991. DOI: 10.7146/math.scand.a-12358. Disponível em: https://www.mscand.dk/article/view/12358. Acesso em: 4 may. 2024.