SKRUNDZ, Valentina V.; SAFONOVA, Inna N. On Shemetkov’s problem of describing critical formations in the class of τ-closed σ-local formations. Journal of the Belarusian State University. Mathematics and Informatics, [S. l.], n. 1, p. 163–178, 2026. Disponível em: https://journals.bsu.by/index.php/mathematics/article/view/7535. Acesso em: 17 jul. 2026.