HINTIKKA, K. Jaakko. An application of logic to algebra. Mathematica Scandinavica, Berkeley, CA, United States, v. 2, p. 242–245, 1954. DOI: 10.7146/math.scand.a-10411. Disponível em: https://journals.msp.org/mscand/article/view/2913. Acesso em: 25 jul. 2026.