EISENBERG, Murray. A Note on Positively Expansive Endomorphisms. Mathematica Scandinavica, Berkeley, CA, United States, v. 19, p. 217–218, 1966. DOI: 10.7146/math.scand.a-10812. Disponível em: https://journals.msp.org/mscand/article/view/2529. Acesso em: 25 jul. 2026.