GLADKOV, Alexander L.; KAVITOVA, Tatiana V. Letter to the editors. Journal of the Belarusian State University. Mathematics and Informatics, [S. l.], n. 1, p. 33–34, 2019. Disponível em: https://journals.bsu.by/index.php/mathematics/article/view/927. Acesso em: 7 oct. 2026.