YESHKEYEV, A.R. Method of the rheostat for studying properties of fragments of theoretical sets. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 100, n. 4, p. 152–159, 2020. DOI: 10.31489/2020m4/152-159. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/397. Acesso em: 4 sep. 2025.