ARMENDARIZ, Efraim P. On infinite periodic rings. MATHEMATICA SCANDINAVICA, [S. l.], v. 59, p. 5–8, 1986. DOI: 10.7146/math.scand.a-12149. Disponível em: https://tidsskrift.dk/math/article/view/12149. Acesso em: 14 aug. 2026.