YOUNG, G. S. Extensions of Liouville’s Theorem to $n$ Dimensions. Mathematica Scandinavica, Berkeley, CA, United States, v. 6, p. 289–292, 1958. DOI: 10.7146/math.scand.a-10553. Disponível em: https://journals.msp.org/mscand/article/view/2797. Acesso em: 25 jul. 2026.