GOODSTEIN, R. L. Diophantine Equations in Recursive Difference. Mathematica Scandinavica, Berkeley, CA, United States, v. 15, p. 43–48, 1964. DOI: 10.7146/math.scand.a-10725. Disponível em: https://journals.msp.org/mscand/article/view/2621. Acesso em: 25 jul. 2026.