JONDRUP, S. Rings in Which Pure Ideals are Generated by Idempotents. MATHEMATICA SCANDINAVICA, [S. l.], v. 30, p. 177–185, 1972. DOI: 10.7146/math.scand.a-11073. Disponível em: https://tidsskrift.dk/math/article/view/11073. Acesso em: 14 aug. 2026.