YESHKEYEV, A.R. Companions of the fragments in the Jonsson enrichment. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 85, n. 1, p. 41–45, 2017. DOI: 10.31489/2017m1/41-45. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/143. Acesso em: 7 sep. 2025.