FILIPCZAK, Małgorzata; HORBACZEWSKA, Grażyna. Some kinds of sparseness on the real line and ideals on ω. Annales Mathematicae Silesianae, [S. l.], v. 34, n. 1, p. 45–50, 2020. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/13631. Acesso em: 3 jul. 2025.