ALIN, J. S.; ARMENDARIZ, E. P. A Class of Rings Having All Singular Simple Modules Injective. Mathematica Scandinavica, Berkeley, CA, United States, v. 23, p. 233–240, 1968. DOI: 10.7146/math.scand.a-10915. Disponível em: https://journals.msp.org/mscand/article/view/2438. Acesso em: 25 jul. 2026.