ZELINSKII, Yu. B.; MOMOT, I. V. On $(n, m)$-Convex Sets. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 53, n. 3, p. 422–427, 2001. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4263. Acesso em: 6 dec. 2025.