GOODSTEIN, R. L. On non-constructive theorems of analysis and the decision problem. Mathematica Scandinavica, Berkeley, CA, United States, v. 3, p. 261–263, 1955. DOI: 10.7146/math.scand.a-10444. Disponível em: https://journals.msp.org/mscand/article/view/2876. Acesso em: 25 aug. 2026.