HINDMAN, Neil; PLEASANT, Kendra. Central Sets Theorem for Arbitrary Adequate Partial Semigroups. Topology Proceedings, [S. l.], v. 58, p. 183–206, 2020. Disponível em: https://www.topologyproceedings.org/index.php/tp/article/view/54. Acesso em: 30 jun. 2026.