SHELAH, Saharon. Preserving Old ([ω]N0, *) is Proper. Sarajevo Journal of Mathematics, [S. l.], v. 13, n. 2, p. 141–154, 2018. Disponível em: https://www.sjm.anubih.ba/index.php/sjm/article/view/91. Acesso em: 26 jan. 2026.