YERBOL KENZHEGALIULY MUKHAMBETGALIYEV. HIGH-ASH COALS - POTENTIAL RESOURCES FOR FERROALLOY PRODUCTION . «Доклады НАН РК», [S. l.], n. 3, p. 12–19, 2020. Disponível em: http://189185.vm7pq.group/reports-science/article/view/801. Acesso em: 22 фев. 2025.