WERNER, Dirk. The Perfekt theory of $M$-ideals. MATHEMATICA SCANDINAVICA, [S. l.], v. 128, n. 2, 2022. DOI: 10.7146/math.scand.a-132230. Disponível em: https://tidsskrift.dk/math/article/view/132230. Acesso em: 13 aug. 2026.