SIMMONS, H. A Possible Characterization of Generic Structures. Mathematica Scandinavica, Berkeley, CA, United States, v. 31, p. 257–261, 1972. DOI: 10.7146/math.scand.a-11432. Disponível em: https://journals.msp.org/mscand/article/view/2212. Acesso em: 25 jul. 2026.