ARA, P.; PERERA, F. Non-stable $K$-theory for $QB$-rings. MATHEMATICA SCANDINAVICA, [S. l.], v. 100, n. 2, p. 265–300, 2007. DOI: 10.7146/math.scand.a-15024. Disponível em: https://www.mscand.dk/article/view/15024. Acesso em: 5 may. 2024.