ANDERSSON, R. Unbounded Soboleff Regions. MATHEMATICA SCANDINAVICA, [S. l.], v. 13, p. 75–89, 1963. DOI: 10.7146/math.scand.a-10690. Disponível em: https://www.mscand.dk/article/view/10690. Acesso em: 4 may. 2024.