VYHOVS'KA, I. Yu.; ZELINSKII, Yu. B. Criterion for convexity of a domain of a Euclidean space. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 60, n. 5, p. 709–711, 2008. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3189. Acesso em: 6 dec. 2025.