FORELLI, Frank. A Maximal Algebra. Mathematica Scandinavica, Berkeley, CA, United States, v. 30, p. 152–158, 1972. DOI: 10.7146/math.scand.a-11071. Disponível em: https://journals.msp.org/mscand/article/view/2252. Acesso em: 25 jul. 2026.