KOUA, Konin. Un example d’algèbre de Banach commutative radicale a unité approchée bornée sans multiplicateur non trival. Mathematica Scandinavica, Berkeley, CA, United States, v. 56, p. 70–82, 1985. DOI: 10.7146/math.scand.a-12088. Disponível em: https://journals.msp.org/mscand/article/view/1533. Acesso em: 25 jul. 2026.