SAPELKIN, A. I. $P$-Faithful Partially Ordered Sets. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 10, p. 1381–1395, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4176. Acesso em: 5 dec. 2025.