STRAY, Arne. Simultaneous approximation in the Dirichlet space. Mathematica Scandinavica, Berkeley, CA, United States, v. 89, n. 2, p. 268–282, 2001. DOI: 10.7146/math.scand.a-14341. Disponível em: https://journals.msp.org/mscand/article/view/864. Acesso em: 24 jul. 2026.