STRÖMBECK, P. On the Spectral Category of Some Rings. MATHEMATICA SCANDINAVICA, [S. l.], v. 33, p. 213–228, 1973. DOI: 10.7146/math.scand.a-11485. Disponível em: https://www.mscand.dk/article/view/11485. Acesso em: 1 may. 2024.