YESHKEYEV, A.R. About central types and the cosemanticness of the ∆-PM fragment of the Jonsson set. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 87, n. 3, p. 51–58, 2017. DOI: 10.31489/2017m3/51-58. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/167. Acesso em: 10 jul. 2025.