The 10th scientific session of the mathematical commission of the T. G. Shevchenko scientific society. Neliniini Kolyvannya, [S. l.], v. 3, n. 3, p. 431–431, 2000. Disponível em: https://nosc.imath.kiev.ua/index.php/nosc/article/view/134. Acesso em: 12 apr. 2026.