YESHKEYEV, A.R.; ZHUMABEKOVA, G.E. Companions of fragments in admissible enrichments. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 92, n. 4, p. 105–111, 2018. DOI: 10.31489/2018m4/105-111. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/260. Acesso em: 16 sep. 2025.