Lutsak S.М. The complexity of quasivariety lattices of unary algebras. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 85, n. 1, p. 65–70, 2017. DOI: 10.31489/2017m1/65-70. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/147. Acesso em: 10 jul. 2025.