MORENO SOCIAS, Guillermo. Length of Polynomial Ascending Chains and Primitive Recursiveness. Mathematica Scandinavica, Berkeley, CA, United States, v. 71, p. 181–205, 1992. DOI: 10.7146/math.scand.a-12421. Disponível em: https://journals.msp.org/mscand/article/view/1228. Acesso em: 24 jul. 2026.