YESHKEYEV, A.R.; MUSSINA, N.M. The hybrids of the ∆ − PJ theories. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 98, n. 2, p. 174–180, 2020. DOI: 10.31489/2020m2/174-180. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/355. Acesso em: 4 sep. 2025.