RYAZANOV , V. I. Differentiality criterion after Belinsky and its consequences. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 2, p. 289–294, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7845. Acesso em: 6 dec. 2025.